Category: Growing

Cannabis Lifecycle Guide

In this guide, we’ll walk through the cannabis life cycle. When thinking about growing cannabis, it’s important to understand three basic facts:

Fact 1: Cannabis is an annual plant

Marijuana is known as an ‘annual’ because its entire lifecycle occurs within a year. When grown outdoors, seeds, which have lain dormant through winter, germinate and grow into seedlings in spring; vegetate and mature throughout summer; in fall they flower, producing and pollinating seeds; before dying by winter. The next year, it all begins again.

Fact 2: Cannabis is a dioecious plant

To be dioecious means that each plant (almost) always has only either male or female reproductive organs. Each plant is explicitly male or female. This is important because when growing cannabis for consumption, you want to select only flowers of female plants not pollinated by males; pollinated flowers produce seeds, which drastically reduce potency and flower yield.

Fact 3: Flowering can start either through photoperiodism or automatically.

Most standard strains of cannabis are known as ‘photoperiod,’ because flowering is induced by altering lengths of exposure to light. While nights (periods of darkness) are shorter than 12 hours, cannabis will continue vegetative growth. Once nights are longer than 12 hours, they will begin to develop flowers. Outdoors, this happens in the lengthening nights/shorter days of fall. Indoors, we can choose when this happens by manipulating light and dark hours.

There is another kind of cannabis plant, though, that is ‘auto-flowering’; flowering begins a predetermined amount of time after germination, regardless of exposure to light. The amount of time before flowering varies, based on the individual strain. Every modern strain was bred from a single small hemp plant known as Cannabis Ruderalis, which had the auto-flowering trait, but didn’t produce much THC. Over the years, it has been cross-bred with Cannabis Indica and Cannabis Sativa to raise THC levels. While auto-flowering strains are generally less potent and productive compared to their photoperiod counterparts, the convenience of not worrying about light control makes them a great option in many situations.

Cannabis has three primary states: 1) seedling 2) vegging and 3) flowering

1) Seedling Phase

The seedling phase begins when the young plant first emerges from the seed and extends for the first few weeks of life. Seedlings are born with a pair of small round leaves, called embryonic cotyledons, that formed in the seed. The young seedling uses these leaves to bootstrap photosynthesis and growth processes. In the next days, it will begin building its first true leaves. The initial sets will have a single point, the next three, before finally developing the five- and seven-point leaves that we associate with adult cannabis plants.

The primary objective of the seedling phase it to allow the plant to develop hearty leaves for photosynthesis, healthy roots to slurp water and nutrients, and a sturdy stem to support the plant. It’s best to let the seedling do its job with minimal interference from the grower.

Seedling Care

Lights

Provide ample light, though not too bright, for over 12 hours each day. Compact fluorescent light, low powered LED, or a window sill will do fine. There are indications that 24 hours of light per day can harm the vascular systems of young cannabis plants, so we recommend between 16 and 18 hours of light per day while for seedlings. Learn more about lighting options and schedules here.

Temperature/Humidity

During the seedling stage, we are trying to replicate warm spring conditions – ideal temperatures are between 70° and 80°F, and should never drop below 60°F. Seedlings benefit from higher air humidities while root structures are forming, 60-70% being ideal.

Water/Nutrients

Water should have a pH level balanced between 5.5 and 6.5. Watering seedlings are simple if you follow these two basic rules:

DO keep the soil warm and moist throughout the seedling phase.
DO NOT flood or over-saturate the soil (no sitting water), as this will prevent the roots from getting enough oxygen, and block access to nutrients. Too much water and the seedling will ‘damp out’ and fail.

Young seedlings get all the nutrients they need from water and light, and excessively high levels of nutrients in the soil will ‘burn’ their leaves. Peat plugs have almost no nutrient content, making them ideal mediums for young seedlings. Learn more about watering and nutrients here.

Transplanting

The best practice is to keep plants in containers suitable to their size. If the container is too big for the plant to use all the water, they tend to damp out from oxygen deprivation. If the container is too small, the plant can become ‘root-bound’ and cease growing. Start off with small containers for small plants, and transplant to bigger ones as they grow. Learn more about containers and transplanting here.

Training & Pruning

Young seedlings are tender, and under rapid development, and so shouldn’t be trained or pruned at this stage. Droopy seedlings can be propped up with a stake.

2) Vegetative Phase

The vegetative phase begins when the young cannabis plant starts producing five- and seven-point leaves. At this point, the young plant will need to start consuming large quantities of water, light, and other nutrients, as they enter this stage of rapid growth.

The primary objective during the vegetative phase is to create as many bud sites and as much plant mass as possible while training the plant into the final growth shape before flowering begins. We do this through training, topping and selective pruning. Cannabis plants in the vegetative stage are incredibly robust and quickly regenerate from injuries, pests, and nutrient deficiencies. Once a plant enters the flowering stage, it becomes much less resilient and pliable, so use the vegetative stage to position your plant, so to make the most out of flowering.

Vegetative Care

Lights

Provide ample bright lights for over 12 hours per day. High powered LEDs or HPS are recommended for the most productive grows. Learn more about lighting options and schedules here.

Temperature/Humidity

During the vegetative stage, we are trying to replicate summer conditions. Ideal temperatures are between 70° and 85°F (21°C-30°C) and should not go above 90°F (32°C) or below 60°F (15°C). Vegetating plants need less humidity than seedlings since their mature roots can pull ample moisture from the soil. Increased humidity increases the risk of mold, rot, and pests, so keep the relative humidity around 50%. For optimal conditions, start vegging at 60%, and lower to 45-50% through vegetation.

Water/Nutrients

For watering, vegetating plants follow the same rule as all other phases:

DO keep the soil warm and moist throughout the vegetation phase.
DO NOT flood or over-saturate the soil, since this will prevent the roots from getting enough oxygen, and cause other nutrient deficiencies.

A good rule of thumb is to wait until the top two inches of medium (knuckle deep) is dry before watering again. Another method is to gauge from the weight of the plant. If you see the leaves start wilting, you’ve waited too long. Have no fear though, young cannabis plants are amazingly strong and resilient, and will most likely bounce back!

Vegetating plants use macronutrients for basic building blocks in its rapid growth process. During the vegetative phase, nitrogen is essential, and potassium less so – though those roles reverse during flowering. Vegetating plants also need micronutrients, like iron, calcium, and zinc, but too many micronutrients can block access to macronutrients. Most nutrients are only available to the plant at specific pH ranges. Using balanced, multi-faceted nutrient systems are the best mechanism to ensure your plants get everything they need. Learn more about watering and nutrients here

Transplanting

Make sure to transplant vegging plants as they outgrow their current container, and that they are in their final container before starting to flower. Learn more about containers and transplanting here.

Training & Pruning

Vegetating cannabis grows rapidly; we call it weed for a reason! Since our primary objective in the vegetative state is to get into the desired shape, we use a variety of techniques available to manipulate vegetating plants, including training, topping, cutting and breaking. Learn about topping here.

3) Flowering Phase

The flowering phase is where the plant produces sex organs. Females will produce the flowers we know as buds. Males will produce pollen sacs, in bunches that look like grapes.

The primary objective during the flowering phase is to grow large, healthy buds. Almost all shaping and manipulation happens during the vegetative stage. During the flowering stage, the stems will become woody and rigid. Flowering plants do not recover from pests, deficiencies, and other accidents so quickly, so you treat your plants with care while they are flowering.

Flowering Care

Lights

Provide ample bright light for less than 12 hours per day. Photoperiod plants require at least 12 hours of uninterrupted darkness per day to flower. If the darkness is interrupted often, the plant will leave the flowering state, and revert to vegetating. High powered LEDs or HPS are recommended for the most productive grow. Learn more about lighting options an schedules here.

Temperature/Humidity

With flowering plants, we are trying to replicate late summer and fall conditions. Ideal temperatures are between 70° and 85°F (21°C-30°C), and should not go above 90°F (32°C) or below 60°F (15°C). Flowering plants need less humidity than in the seedling or vegetative stages. Increased humidity runs the risk of mold, rot, and pests, so keep the relative humidity around 40-45%.

Water/Nutrients

For watering, flowering plants follow the same rule as all other phases:

DO keep the soil warm and moist throughout the vegetation phase.
DO NOT flood or over-saturate the soil, since this will prevent the roots from getting access to enough oxygen, and cause nutrient-deficiencies.

Note: flowering plants are not as resistant to over- and under-watering as vegetating plants.

Flowering plants also need macro- and micronutrients, and it is essential to keep these levels balanced. Unlike the vegetation phase, plants in flower do not require as much nitrogen (too much can slow production) but need increased potassium. Using balanced, multi-faceted nutrient systems will still be the best mechanism to ensure your plants get what they need. Learn more about watering and nutrients here

Transplanting

Cannabis plants should not be transplanted in flower if it can be avoided. Since transplanting is incredibly stressful, you should make every effort to have the plant in its final container before starting flower. If transplanting cannot be avoided, use extreme care in transplanting to minimize stress and damage.

Training & Pruning

Vegetating cannabis grows rapidly, and is extremely resilient to both high and low-stress training. This is NOT the case for flowering plants and you should not cut, injure or perform any other high-stress activity on your flowering plant. After a few weeks of flowering, the plant will become rigid, and vertical growth will slow – at which point even LST techniques should no longer be used.

Prune your flowering plants selectively. I remove small bud sites from the understory to focus growth on the big buds up top. You can also pull fan leaves that are damaged or excess fan leaves for additional airflow. Always be gentle with your flowering plant, and never take too much at one time.

Life Cycle FAQs

How long does it take to raise a cannabis plant from start to finish?

For photoperiod plants, the amount of time will vary based on how long you keep it in vegetation before you switch to flower. Since you can induce flowering immediately after seedling (3 weeks old), and most strains take at least eight weeks in flower, 10 to 11 weeks is the minimum possible. The longer you leave the plant in veg, the larger the flowering plant will be.

Vegging your plant for 1 to 2 months will drastically improve yields.

Learn More

Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
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Harvesting Guide

Its an exciting time! You’ve spent tons of time and energy into growing your crop and its finally getting close to harvest time and its tempting to claim victory and get busy reaping the rewards. There are 3 steps left though:

  • Harvest the plant
  • Dry the flowers
  • Cure the bud

You’ve invested too much time and energy to rush past the last steps. Harvesting too early can drastically decrease potency, since the THC has not finished maturing. If the buds aren’t dried enough, they can grow mold. Don’t cure for long enough and your bud will taste like hay and may make you anxious or paranoid. In this guide, we will cover when to harvest, how to dry and cure your bud for the best results.

When is the best time to harvest?

The amount of time spent in flowering varies by strain, but generally, your buds will be ready to harvest 8-12 weeks after flowering starts. There are two simple methods for determining when your cannabis plants are ready for harvest that will optimize potency, and give the best-finished product overall.

Most Precise: After a percentage of trichomes have turned milky or cloudy
Simplest: After a portion of pistils have darkened in color.

This buds look close to harvest, but you’ll need to look closer to harvest at the perfect time.

Using Trichome Color

Trichomes are mushroom looking structures that form the crystal structures on flowers – often referred to as resin – that contain the cannabinoid compounds we all love. To the naked eye, trichomes appear as the white dust that forms on the flowers and sugar leaves growing out of the bud structure. The ‘Fruity Jack’ from Philosopher Seeds above shows extreme trichome growth.

Young trichomes are clear when they first form and turn milky white as they mature. Trichomes that have just turned white are higher in the psychoactive compounds (like THC) that create cerebral effects. Fully mature trichomes turn amber and are higher in compounds like CBD and lower in THC, thus causing sedating or ‘couch-lock’ type effects. Counting the percentage of trichomes that have turned amber will let you know exactly when to harvest.

WhiteAmberEffect
100%0%Highest psychoactive
80%20%High psychoactive effect
50%50%Balanced effect
20%80%Raised sedative and lowered psychoactive
0%100%Most sedative

The images below show trichome development as the plant matures.

Clear Trichomes = Not Ready
All White Trichomes = Highest Psychoactive
Some Amber Trichomes = Balanced Effects
Mostly Amber Trichomes = Sedative Effects

To observe the trichomes up close, you will need a strong magnifying glass, jewelers loop, or handheld microscope. Measure the percent of clear versus milky trichomes on several buds and take the average.

Using Pistil Color

While not as precise as looking at the trichomes, this is the simplest method since it requires no additional equipment. The white hairs growing out of young marijuana buds are called pistils. As the flowers mature, the pistils darken into brown or red colors.

Light PistilsDark PistolsEffect
50%50%High psychoactive & milder sedative
25%75%Balanced
10%90%Raised sedative & lowered psychoactive

You can observe pistil color with your eye alone. Measure the percent light versus percent dark on several buds, and take the average. The pistils in the ‘Purp Pac’ below show that it is almost ready to provide a balanced effect.

This plant is ready, with almost all dark pistils, resulting in an increased sedation effect.

Getting Ready

As your plants are getting closer to harvest, there are a few things you’ll want to do to get ready.

Flush

Cannabis nutrients can leave behind salts and other trace residues that can negatively impact the smell, taste, and overall quality of the final buds. You can clean most of these from your plants a week or so before harvest with a nutrient flush.

To flush, use large amounts of water (or optionally with a flushing solution) to remove leftover nutrients and salts from the soil. Use at least an equal quantity of water to the size of the container. Flushing two weeks before harvest and using only organic nutrients for the rest of flowering can improve the buds flavor and make it smoke cleaner.

Prune Fan Leaves

It’s often easier to remove fan leaves while the plant is still standing, so many farmers snap them off in the weeks before harvest. To do this safely, grab the leaf stalk at the base and pull upwards while snapping the stalk. If you don’t pull upwards, the stalk will pull bark off the stem, and cause extra stress to the plant.

Extended Darkness

Many farmers believe that extending hours of darkness near harvest can improve resin production as the plant believes that the season is almost over, and kicks growth into overdrive. While the science behind this isn’t clear, it doesn’t seem to hurt.

Harvest

This one is easy: cut the plant at the base of the stalk.

Dry

To dry the plant, hang it up. You can hang the entire plant or cut off individual branches. You will remove and manicure the individual buds from the branches AFTER they are dried.

Keep the relative humidity between 30% & 60% and the temperature between 65F & 80F (18C & 26C). Avoid too much airflow to keep the plant from drying too fast.

You can dry right in your tent – hang your plants between 3 and seven days.

If drying takes less than three days, you are drying too fast and want to increase humidity, decrease air-flow, or decrease temperature next time. If drying takes more than seven days, you are drying too slow and will want to reduce humidity, increase air-flow and temperature next time.

When is it dry?

Dry cannabis flowers have the following properties:

  • The outside of the bud is crispy and dry.
  • The inside is still moist and supple.
  • When you press it, it should retake its shape.
  • The small stems are crispy and snap easily.
  • The large stems do not yet snap.

What if I let it dry too much?

This is recoverable during the curing phase in most cases, as the cannabis will reabsorb moisture from humidity packs.

What if I I didn’t let it dry enough?

Just let it finish drying. Weed that is packaged wet will always have a funky smell, might grow mold, will smoke poorly, and will generally not be a great experience. Just put these back out to dry.

Is it ready to smoke now?

Kind of. Dried cannabis is technically smokable, but won’t burn as clean, flagrantly, or as smooth as it will after curing. Uncured cannabis can also cause increased anxiety and uncomfortable feelings. Curing your weed correctly will make sure that you get the most out of the time, energy and money you’ve invested in your garden.

Is there an easier way to dry and cure?

Professionally made equipment, including drying racks and curing containers can help. Check out this list for more information.

Cure

The curing phase is when your cannabis will improve its flavor profile and increase potency over a series of natural processes. During this time, you want to keep a stable humidity between 50% and 60% with reduced airflow.

Step 1: Remove and manicure buds from stem.

This is a messy step and your hands will get sticky! Using scissors or shears, cut the buds off the stems and then manicure sugar leaves. How much you focus on making the buds look pretty is up to you. Just make sure you save the shake (stuff you cut off) since it can be used to make edibles and extracts.

Step 2: Put in glass jars.

Put the cannabis into glass jars (1 qt/liter jars work the best). Just drop the manicured buds in, do not pack them into the jar or they will become overly compressed and not cure. Drop a humidity pack in the middle of the jar, and then close the lid.

Step 3: Wait.

Cannabis benefits heavily from curing for the first 6 weeks, and then has diminishing returns. For the first couple of weeks, open the container once or twice a day to let it breath for 5-10 minutes.

Step 4: Smoke!

After curing for at least a few weeks minimum, your cannabis is ready to smoke! Enjoy, you’ve earned it.

How important is the curing step?

Very. If you skip it, your pot will be less potent and more likely to cause anxiety and negative feelings. The temptation to sample is high when the buds look and smell so amazing, but it’s worth the wait. We recommend a full six weeks, but there’s no law against sampling a little along the way.

Learn More

Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
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Flowering Care Guide

In this guide, we’ll walk through caring for your marijuana plants during the flowering stage. The flowering stage is the final stage of the plant’s life and begins after darkness lasts longer than 12 hours for photoperiod strains or after a set amount of time for auto-flowering strains. During this phase, the plant will produce sexual organs in an attempt to procreate before dying. Females produce the flowers that we all like to smoke and male plants produce pollen sacs, which aren’t good for anything other than causing the females to produce seeds. If you are growing bud to smoke, you want to remove any males as soon as you identify them.

Primary Objective: The objective during this phase is for your plants produce flowers or buds. At the beginning of flowering, most strains will put on rapid vertical growth that often causes them to double in height.

Optimal Environment: Think late summer and early fall, with cooling temperatures and decreasing humidity. Along the edge of the forests, the adult plants will rustle in the gentle winds as they reach toward the waning sun that shines for less than 12 hours a day. Rains come frequently but with time to dry the soil between. Building large bud structures requires nutrients high in phosphorus and potassium.

Flowering Care

Grow Space

Most strains tend to stretch at the beginning of flower, often doubling in height. Make sure you have ample vertical grow space to account for this.

If you are growing photoperiod strain, you will need to make sure that your grow space can be completely dark for over 12 hours per day. Even a quick flash of light can be enough to interrupt the flowering cycle. Grow tents are ideal for light control, but cabinets or closets work well too.

Learn more about grow spaces here..

Lights

Provide ample bright lights for under 12 hours per day. Photoperiod plants require at least 12 hours of uninterrupted darkness per day to flower. If the darkness is interrupted often, the plant will leave the flowering and revert to vegging. High powered LEDs or HPS are recommended for the most productive grow. During flowering, you can place the lights closer to the plants than in vegetative growth, but generally keep LEDs at least 12 inches (30cm) away. Learn more about lighting options and schedules here.

Fruity Jack from Philosopher Seeds under LED lights.

Temperature/Humidity

With flowering plants, we are trying to replicate late summer and fall conditions. Ideal temperatures are between 70 and 85F (21C-30C) and should not go above 90F (32C) or below 60F (15C). Flowering plants need less humidity than seedlings or vegging plants. Increased humidity runs the risk of mold, rot, and pests, so keep the relative humidity around 40-45%.

Water/Nutrients

For watering, flowering plants follow the same rule as all other phases:
DO keep the soil warm and moist throughout the vegetation phase.
DO NOT flood or saturate the medium, since this will prevent the roots from getting enough oxygen. Too much water and the seedling will suffer root and nutrient problems and will eventually fail. Flowering plants are not as resistant to over watering and under watering as vegetating plants.

Flowering plants also need macronutrients for basic building blocks in the budding process. Unlike the vegetation phase, plants in flower do not need as much nitrogen (too much can slow production) but need increased phosphorus and potassium. Flowering plants need micronutrients also, like iron, calcium, zinc, etc. Too many micronutrients can block macro-nutrients. Most nutrients are only available to the plant at specific pH ranges. Using balanced multi-part nutrient systems are the best mechanism to assure your plants get what they need.

Learn more about watering and nutrients here

Leaves often turn yellow in late flower as the plant diverts energy to the flower

Pest Control

Plants in the flowering phase don’t recover from pest outbreaks as easily as vegetating plants, so the key to effective pest control is to be proactive before there is an outbreak. Pests thrive in the same conditions as your plants, so it is inevitable that they will find your crop if you don’t take steps to prevent them from establishing a foothold in the first place. Whether it’s mites, mold or whiteflies, there are a few preventative measures that can help you keep your crops safe:

  • Keep it clean; don’t leave litter, rotting leaves or standing water in your grow space since this provides excellent hiding spots and food sources.
  • Don’t spray the plants right before lights out; water droplets left on the leaves can encourage mold and mildew.
  • Keep proper temperature and humidity; too warm and humid and pests will thrive.
  • Use neem oil treatments at least once a week to make it more difficult for pests to gain a foothold.
  • Treat outbreaks aggressively

It’s safe to spray neem onto the bud sites. Neem has a strong fragrance, so you might want to avoid using it for the last weeks before harvest.

To learn more, read about a balanced approach to handling pests in cannabis, diagnose problems with our troubleshooting guide and how to use neem oil to protect your plants.

Transplanting

Cannabis plants should not be transplanted in flower if it can be avoided. Since transplanting is stressful, you should make every effort to have the plant in its final container before starting flowering. If transplanting cannot be avoided, use extreme care in transplanting to minimize stress and damage.

Training & Pruning

Vegetating cannabis grows rapidly and is extremely robust to both high and low-stress training. During the flowering phase though, your plant becomes less robust to stress and any injury can slow growth. As a general rule, you should not cut, injure or perform any other high-stress activity on your flowering plant. After a few weeks in flowering, the plant will become rigid and vertical growth will slow – at which point even low stress training techniques should no longer be used.

Prune your flowering plants selectively. Removing small bud sites from the understory can focus growth on the big buds up top. You can also pull fan leaves that are damaged or excess fan leaves for additional airflow. Always be gentle with your flowering plant and never take too much at one time.

This LSD from Barney’s Farm seeds had multiple toppings and low-stress training before being put into flower.

Is my plant male or female?

Cannabis plants are dioecious plants, which means that each plant (almost) always has either male or female organs. This is important when you’re growing cannabis to smoke because you only want the flowers of the female plant and you don’t want them to be pollinated by male plants. Pollinated flowers produce seeds, which drastically reduces potency and flower yield.

You can tell the sex of a cannabis plant 5 to 14 days after flowering starts by inspecting the growth tips near the plant’s nodes. Female plants begin growing white hairs, or pistols, out of pointy calyx that will eventually form the bud structures.

Male plants will form tiny grapes like pollen sacs, like in the picture below. These should be removed from your garden as soon as possible to avoid pollinating female plants. Male plants almost never produce substantial amounts of THC.

This Cooley from Cizzle is a male – notice the grape-like sacs forming.

When is the flowering phase over?

The flowering phase is over when your buds are ready to harvest. It varies by strain, but generally, your buds will be ready to harvest between 8 to 10 weeks after flowering starts. There are two simple methods for determining when your cannabis plants are ready for harvest:

Most Precise: After a certain percentage of trichomes have turned milky or cloudy
Simplest: After a certain percentage of pistils have darkened

Learn all about when and how to harvest here.

Most common problems can be diagnosed by inspecting the leaves.

What’s wrong with my plant?

Sometimes things don’t go the way you planned, and it seems that no matter how careful you are, things are going to go off the rails with cannabis sometimes. Unfortunately, there isn’t a lot of time to correct issues. Mite, mold and other pests can also wreak havoc on your crops, so you need to act quickly.

Nutrient deficiencies are common in flowering plants. Nitrogen deficiency is even normal, as the plant needs much less nitrogen during flowering. Other deficiencies are often caused by pH balancing problems, and not a lack of nutrients in the medium. These are simple to diagnose and easy to correct, but need to be addressed quickly in flowering plants.

Learn how to diagnose and correct problems with our troubleshooting guide.

Learn More

Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
Read more

Vegetative Care Guide

In this guide, we’ll walk through caring for your marijuana plants during the vegetative stage. The arrival of the fully formed seven-point leaves found in mature plants marks the beginning of this phase. The first leaves of a newly-sprouted seedling will have a single point; the next three, then five points; before finally producing the iconic seven-point leaf, which signifies the beginning of the vegetative stage. This phase is where your plant will do a lot of its growth, both vertically and horizontally.

Primary Objective: The objective during this phase is to put on as much plant mass and create as many bud sites as possible while training the plant into the final growth shape before entering flowering. We do this through training, topping and selective pruning. Cannabis plants in the vegetative states are incredibly robust and quickly regenerate from injuries, pests and nutrient deficiencies. Once a plant enters the flowering stage, it becomes much less pliable and robust to manipulation, so use the vegetative state to position your plant to make the most out of flowering.

Optimal Environment: Think late spring through summer, with warming temperatures but decreasing humidity. Along the edge of the forests, the young plants will rustle in the gentle winds as they reach toward the bright sun that shines for 16 to 24 hours a day. Rains come frequently but with time to dry the soil between wettings. The explosive growth needs strong roots to pull nutrients from the fertile soil.

Vegetative Care

Grow Space

There are lots of options for where you grow, and your selection will depend on your goals and constraints.

Outside – Cannabis can spend their vegetative cycle outside during the summer months.
Space Bucket – These are self-contained environment-in-a-bucket are perfect for single plant stealth grows.
Grow Box – They are a great option for small and stealthy grows for single plant production. You can pick these up premade or make your own or repurpose an old piece of furniture.
Closet – A spare closet can make an ideal grow space because they offer good height and are good at keeping light contained. You will need a fan for ventilation in most closets.
Grow Tent – Grow tents range in size, from 2’x2′ (.6m x .6m) on up and are great options for all phases on cannabis life. Tents have great ventilation, reflective walls to make efficient use of lighting and they keep light contained to keep your grow stealthy.

Learn more about grow spaces here.

Vegetative phase begins after the plant start producing adult leaves.

Lights

Photoperiod strains will enter flowering if dark periods exceed 12 hours, so nights must be kept shorter than 12 hours to keep the plants in vegetative growth. Auto-flowering strains, on the other hand, go into flower a set amount of time after germination.

Farmers describe light cycles as a ratio of light/dark hours. Standard options are 18/6 (18 hours of light followed by 6 hours of dark), 20/4 (20 hours of light followed by 4 hours of dark) and even 24 hours of light without darkness.

While the general rule of thumb is that more hours of light means more photosynthesis which means more growth potential, there are indications that dark periods are essential in plant development – particularly in root growth.

Lighting Options

Sunlight – Vegging your plant in sunlight is a great option – particularly if supplemented with an artificial option.
Fluorescent Compact Fluorescent Lights (CFL) and fluorescent tube lights can be great options for vegging plants. They are cheap, burn relatively cool and are readily available.
LED – Over the past years, LEDs have overtaken almost all other lighting types for home grows. They are relatively inexpensive to purchase and operate and burn very cool compared to traditional grow lights. In nearly all cases, we recommend LED lighting to other sources.
HPS – High-Pressure Sodium lights are incredibly effective lights and have been successfully used to grow amazing buds for decades. They do burn hotter than LEDs, which can cause temperature problems in tents and other confined spaces.

Learn more about lighting options and schedules here.

These vegetating plants have been topped several times to make them bushy

Temperature/Humidity

With vegging plants, we are trying to replicate summer conditions. Ideal temperatures are between 70 and 85F (21C-30C) and should not go above 90F (32C) or below 60F (15C). Vegetating plants need less humidity than seedlings since their mature roots can pull ample moisture from the soil. Increased humidity runs the risk of mold, rot, and pests, so keep the relative humidity around 50%. For optimal conditions, start vegging at 60% and lower to 45-50% through vegetation.

Water/Nutrients

For watering, vegetating plants follow the same rule as all other phases:
DO keep the soil warm and moist throughout the vegetation phase.
DO NOT flood or saturate the medium, since this will prevent the roots from getting enough oxygen. Too much water and the seedling will suffer root and nutrient problems and eventually fail.

A good rule of thumb is to wait until the top two inches of medium (knuckle deep) is dry before watering again. Another method is to gage from the weight of the bag. If you see the leaves start wilting, you’ve waited too long. Have no fear though; young cannabis plants are amazingly robust.

Vegetating plants need macro-nutrients for basic building blocks in its rapid growth process. During the vegetation phase, nitrogen is essential and phosphorous is less critical – though those roles reverse during flowering. Vegetating plants need micro-nutrients too, like iron, calcium, zinc, etc. Too many micro-nutrients can block macro-nutrients. Most nutrients are only available to the plant at specific pH ranges. Using balanced multi-part nutrient systems are the best mechanism to assure your plants get what they need.

Since nutrient requirements and tolerance can vary by plant, it’s a good idea to calibrate the needs of each plant. Start off with around 1/4th recommended dosage and then gradually increase until you hit the right level. The bottom leaves will begin to yellow if there aren’t enough nitrogen and leaf tips will burn if there are too many nutrients.

Learn more about watering and nutrients here

Pest Control

The key to effective pest control is to be proactive before there is an outbreak. Pests thrive in the same conditions as your plants, so it is inevitable that they will find your crop if you don’t take steps to prevent them from establishing a foothold in the first place. Whether it’s mites, mold or whiteflies, there are a few preventative measures that can help you keep your crops safe:

  • Keep it clean; don’t leave litter, rotting leaves or standing water in your grow space since this provides excellent hiding spots and food sources.
  • Don’t spray the plants right before lights out; water droplets left on the leaves can encourage mold and mildew.
  • Keep proper temperature and humidity; too warm and humid and pests will thrive.
  • Use neem oil treatments at least once a week to make it more difficult for pests to gain a foothold.
  • Treat outbreaks aggressively

Plants in the vegetative state heal faster than plants in the flowering stage, so it’s a good idea to make sure you have pests under control before transitioning to flower.

To learn more, read about a balanced approach to handling pests in cannabis, diagnose problems with our troubleshooting guide and how to use neem oil to protect your plants.

Transplanting

A small plant in a big pot causes problems because it is difficult to get the correct mixture of water and air for the roots. A large plant in a small pot with drastically slow growth. Start plants in an appropriately sized container and then transplant vegging plants as they outgrow their current container. Make sure that they are in their final container before starting to flower.

Learn more about containers and transplanting here.

Training & Pruning

Vegetating cannabis grows rapidly; we call it weed for a reason! Since our primary objective in the vegetative state is to get into the desired shape, this is the time to get the plant into a shape that will best take advantage of your grow space. There are a variety of techniques available to manipulate vegetating plants.

Why do I want to train and prune?

Cannabis plants naturally grow into a shape similar to a Christmas tree. Some cannabis strains can grow 20 feet (6 meters) in just a few months. Growing plants that size won’t work for most home grows, so we use a variety of techniques to shape the plant to optimize for the space available.

Topping and training during the vegetative phase produces many large buds to increase yield and make better use of indoor lights during flower.

Low-Stress Training (LST): A mechanism for engineering cannabis growth by gentle and persistent manipulation of growing shoots through bending and shaping. It does not involve cutting, breaking, damaging or performing other stressful activities to the plant. The goal of LST is to develop the plant for optimal flower production later in life by continually pulling the tallest vertical branches and securing them to grow horizontally. Training the plant’s side branches to grow horizontally produces a flat canopy to make efficient use of indoor lighting.

Learn about how to combine topping and LST to boost your crops in our Low Stress Training guide.

Topping & FIM’ing: A mechanism that involves cutting or pinching the growing tips of the cannabis plant to break apical dominance and encourage branching. Apical dominance is when the principal, central stem of the plant is dominant over other side stems. Apical dominance causes cannabis to naturally grow in the traditional Christmas Tree shape with one large bud at the cola and smaller buds on side branches. Its an excellent form for growing cannabis under the sun (large light source far away) but does not work well for indoor lights (a small light source close up). Breaking this dominance allows multiple large colas and a flatter surface area for more massive indoor production. Since topping can stress to the plant, it can slow growth for a few days.

If you are growing an auto-flower with a short veg cycle, you will probably want to skip topping and rely on LST techniques.

Learn more about Topping & FIM’ing here..

Super-cropping: Another HST technique that increases yield and potency and encourages bushier growth. With super-cropping, the main stem is twisted and damaged in a specific way, so that when the plant regenerates it with improve vascular capabilities and some theorize that the stress can cause the plant to produce additional THC as a defense mechanism.

Pruning: Pruning is a hotly debated topic in cannabis circles. Some people claim that it harms the plant to remove fan leaves, and you should instead remove bud sites that aren’t getting enough light instead. We have found that both are helpful:
Pruning excess leaves can reduce humidity and improve airflow
Pruning branches and bud sites from lower on the plant, where they receive less light and would never develop past the pop-corn size anyway, divert resources back to buds on the top.

If you choose to prune, try to avoid mass pruning as that can cause stress and even shock that will slow the plant’s growth. Instead, remove a few leaves or bud-sites at a time. Look at it as a continuous process throughout the veg state.

When Is The Vegetative Phase Over?

In photoperiod strains, the vegetative stage lasts as long as the plant gets less than 12 hours of uninterrupted darkness per day. In nature, this continues from spring to early fall. Plants will begin the flowering stage after nights lengthen to 12 hours of continuous darkness. Indoor growers can end the vegetative stage and start flowering by setting the light schedule to 12/12 (12 hours of light followed by 12 hours of uninterrupted darkness). Controlling the light cycle allows you to decide, based on space and goals, to determine how long to vegetate your plants.

Autoflowering strains, on the other hand, begin flowering after a set number of days from germination regardless of the lighting schedule. The advantage is that you don’t have to worry about lighting schedules as much, but you also lose some control.

Most common problems can be diagnosed by inspecting the leaves.

What’s wrong with my plant?

Sometimes things don’t go the way you planned, and it seems that no matter how careful you are, things are going to go off the rails with cannabis sometimes. Luckily, vegetating plants are very robust and most common problems are are easy to diagnose and simple to fix.

Nutrient deficiencies are common in vegging plants, especially nitrogen deficiencies. Often caused by pH balancing problems, and not a lack of nutrients in the medium, these are simple to diagnose and easy to correct.

Mite, mold and other pests can also wreak havoc on your crops. Luckily, these are easy to treat in the vegetative state, and there is plenty of time for your plant to recover before you put it into flower – unless it’s an auto-flower.

Learn how to diagnose and correct problems with our troubleshooting guide.

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Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
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Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when the young plant first emerges from the seed and extends for the first few weeks of life. Seedlings are born with a pair of small round leaves called ‘embryonic cotyledons,’ that formed inside the seed. The young seedling uses these leaves to bootstrap photosynthesis and growth processes through the seedling phase, which ends after the plant starts growing adult leaves with 5 and 7 points.

Primary Objective: During the seedling phase, the primary objective is to allow the plant to develop hearty leaves for photosynthesis, healthy roots to slurp water and nutrients and a sturdy stem to support it all. It’s best to let the seedling do its job with minimum disturbance from the grower.

Optimal Environment: Think warm spring days in a humid understory, at the edge of a clearing. The light would be bright, but not too intense, and would shine between 12 and 16 hours a day. The soil would be mostly dry between rains, and temperatures would be between 70°F-80°F (21°C-26°C) with 60-80% humidity. In this environment, the young plant would spend the first weeks of her life developing its first sets of true leaves. The first sets will have one point, the second will have 3 points, the next 5 points, before finally producing the iconic 7-point leaf. Under the soil, the roots will begin spreading throughout the medium, looking to establish a solid base in the thick understory.

Seedlings do well in small containers.

How do I care for a seedling?


Lights

Provide ample light, but not too bright, for over 12 hours per day. Compact fluorescent light, low powered LED, or a window sill would all be ideal sources. There are indications that continuous light, without periods of darkness, can harm the vascular systems of young cannabis plants, so we recommend between 16 and 18 hours of light per day for seedlings.

Temperature/Humidity

With seedlings, we are trying to replicate warm spring conditions. Ideal temperatures are between 70°F and 80°F, and should never drop below 60°F. Seedlings benefit from higher air humidities while the root structures are forming, between 60% and 70% being ideal.

Water/Nutrients

Water should be pH balanced between 5.5 and 6.5. Watering seedlings are simple if you follow these two basic rules:

DO keep the soil warm and moist throughout the seedling phase.

DO NOT flood or saturate the soil, since this will prevent the roots from getting enough oxygen. Too much water and the seedling will ‘damp out’ and will fail.

Young pot seedlings do not need very many nutrients and nutritional content in the growing medium that is high will ‘burn’ their young leaves. Peat plugs have almost no nutrient content, making them ideal mediums for young seedlings. After the first few weeks, you may begin to notice lower leaves yellowing slightly; this is the plant asking for nitrogen. Start off with a light compost tea, or diluted nutrients at ~25% of the recommended dose; then ramp up over the coming weeks. Remember though, if the leaf tips begin to burn that this is a sign that nutrient levels are too high, and to back off a little. Tolerance – or need – for nutrients varies by strains, and even by the individual plant, so you’ll need to use trial and error to find the happy medium.

Pest Control

Seedlings are fairly tender, so avoid using even neem oil on them – never mind strong chemical treatments. For the first weeks, pests should not be a major problem for your seedlings if you follow a few preventative measures that can help you keep your seedlings safe:

  • Always start your seedlings in a clean, pest-free environment
  • Keep it clean; don’t leave litter, rotting leaves or standing water in your grow space since this provides pests with hiding spots and food sources.
  • Don’t spray the plants right before lights out; water droplets left on the leaves can encourage mold and mildew.
  • Keep proper temperature and humidity; too warm and humid and pests will thrive.

You can learn more about a balanced approach to handling pests here. If you do have pests in your seedlings, remove them from the infected area and try a light neem treatment. Learn more about using neem oil to safely treat cannabis.

This seedling is almost ready to transplant because the leaves are hanging over the pots edges.

Transplanting

It is best practice to keep plants in a suitably sized container for its current stage. If the container is too big, the plant can’t drink up all the water and will tend to damp out from oxygen deprivation. If the container is too small, the plant can become root bound and stop growing. Start off with small containers for small plants, and transplant up as the plants’ root system fills the container.

Training/Pruning

Young seedlings are tender and under rapid development and shouldn’t be trained or pruned. Droopy seedlings can be propped up with a stake, but otherwise the seedling should be left to grow.

When Is The Seedling Phase Done?

There isn’t a definitive moment: once plants start producing the seven-pointed leaves that we associate with adult cannabis, vegetation will begin.

These plants are producing 5 and 7 point leaves, their seedling days are over!

The plants in the picture above have matured and strengthened, and are beginning to produce five- and seven-point leaves. So far they’ve spent their lives under a soft fluorescent light, with only water and a light compost tea. Now they’re ready to be transplanted to larger containers and are showing early signs of nutrient deficiencies, seen in the yellowing leaves at the base of the plant. All of these signs taken together signal the end of the seedling phase, and the beginning of the adult vegetative stage.

Why is my young seedling drooping?

Most often, a drooping seedling is caused by overwatering, known as ‘damping out.’ Let the medium dry out before watering again, and the young seedling might recover.

How can I get the seedling to grow straight?

Even healthy seedlings often droop or grow crooked. You can quickly correct leaning or drooping plants without stressing the plant by staking it up. Take a small wooden or plastic stake and push it into the soil deep enough to stay upright. Attach gardening wire to the stake and tie the plant upright by enclosing it in a loose loop. This low-stress training method will encourage the young plant to grow upright without harming or damaging it.

Staking seedlings does not stress the plant but encourages straight growth.

Why are my seedlings turning yellow?

The plant isn’t getting enough nutrients. Deficiencies often due to a pH imbalance locking out available nutrients or it could be a lack of available nutrients. Check pH first, but if you plant in with entirely inert mediums, like coco and perlite, add gentle nutrients after the first week.

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Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
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Germination Guide

If you are starting with seeds, you’ll have to germinate them to get the grow started. In this chapter, you’ll learn all about the natural conditions that cannabis seeds germinate under and then we’ll show you a failsafe way to germinate your seeds.

This cannabis seedling emerges 3 days after planted directly in soil

What is germination?

A cannabis seed is just an embryonic plant enclosed in a protective shell and germination is the process of reactivation of metabolic machinery of the seed. The outer shell splits apart and the embryonic plant emerges as a seedling. For cannabis seeds, this process takes between 1 and 7 days.

What makes seeds germinate?

Cannabis seeds lie dormant until they meet the right conditions to begin germination. In tropical conditions, cannabis seeds germinate in the warm rains of early spring. The well-drained soil of the forest floor wouldn’t be waterlogged, but it wouldn’t dry out. The ideal temperatures would be between 70°F-80°F (21°C-26°C), with 60-80% relative humidity. These spring seasonal signals tell the embryonic plant contained in the seed that conditions are right to begin its life cycles. These are the same conditions you will emulate to germinate seeds.

What’s the easiest way germinate cannabis seeds?

Peat moss pellets are pucks of dried peat moss enclosed in a fine netting. As a mostly inert medium that retains water well, peat moss pellets do a great job of mimicking the natural conditions of spring jungle floor.

What you need

Peat moss pellets – Get them online or at local department/hardware stores – they are widely available.
Filtered water – You probably have this in your fridge. pH balance between 5.5 and 6.5.
Cannabis seeds – Learn more about cannabis seeds in our guide

Peat Moss pellets swell to 5x their normal volume when flooded with water

Step 1 – Flood the Peat Moss

Peat plugs come dried and compressed, so you need to flood them with water. Use some warm filtered water from your fridge, rainwater, or distilled water that’s pH balanced between 5.5 and 6.5. Add water until the plugs are saturated, then drain the excess water. The plugs will swell 4-5x their original volume.

Step 2 – Insert Seed

Most plugs or pellets have a small hole in the top. Insert the seed between 1/4-1/2″ (6-12MM) deep and lightly cover with an excess medium.
All emerging seedlings look identical, and most mature plants look very similar. If you start multiple strains at once, make sure to label them. Plastic plant labels can be fixed to peat moss plugs to identify the plant through its life – adding dates makes it a self-contained record.

Step 3 – Wait for it!

The next few days is mostly a waiting game. Put the pellets in a partially covered container to prevent drying out and follow these two simple rules:

DO keep the pellets warm and moist throughout germination, cannabis seeds germinate best in these conditions.
DO NOT flood or over-saturate the pellets after the initial flooding, since this will prevent the roots from getting enough oxygen. Too much water and the seedling will ‘damp out’ and fail.

One easy method to ensure that you get the right amount of water is to use a spray bottle to wet the outside edges. Another is to quickly dip the bottom of the pellets into the water; moisture will wick upwards to the rest of the pellets. Either method will encourage roots to grow outward.

This seedling is emerging with the seed still attached – it will fall off in a a day or so.

Step 4 – Care for it!

As your young seedling emerges from the seed, you’ll notice that it has a set of ‘built-in’ leaves that don’t look a lot like pointy cannabis leaves. These are the cotyledons, and they are there to help the young seedling bootstrap the photosynthesis process. Young seedlings need light right away – but not too bright for the first few days

Keep the peat pellet moist until the seedling is ready to plant in a growing medium, but never saturate the pellet since that can drown the young plant. Add water from the bottom up by dipping the pellet quickly in water. This will promote rapid root growth as the roots will grow down after the water.

When is it time to plant the seedlings?
You’ll know when it’s time because roots will be bursting out of the bottom of the peat pellet. Plant the pellet in a solo cup sized container using a quality soil mix. Water without nutrients for the first few weeks.

Optimizations & Alternatives

Germination Heat Mats

Germination heat mats are just like heating pads, but they don’t get as hot and are water resistant. These are especially useful for germinating seeds in colder conditions.

Germination Enclosures

One of the best ways to simulate tropical climates is to use an enclosure to conserve moisture and heat. You can make your own from cheap plastic containers, or buy a special purpose kit made for peat pellets. Used along with a germination heat mat, you can easily set up a tropical jungle climate anywhere.

If you want professional results with no hassle and complete stealth, try a professional grow-box.

Can I germinate seeds in paper towels?

Yes, you can germinate marijuana seeds in moist paper towels. Just put a damp paper towel down on a plate or other container and spread the seeds around. Add another damp paper towel or fold over the existing towel to cover all the seeds. You will need to keep the paper towels damp at all times throughout the germination process – a spray bottle can really come in handy for that. Covering the seeds with another plate or plastic will prevent it from drying out too quickly, just make sure that there is still some airflow for when the seedling emerges.

After a few days, the seed will crack and the embryonic cannabis plant will start to emerge. Once you see a solid root begin to emerge, you will need to transplant it into your growing medium. While this approach might be slightly faster than the other methods we’ve shown here, we don’t use this method because of the risk to the plant and main root during transplanting.

Can I germinate seeds directly in the growing medium?

That’s how it works in nature and it’s easy to do. Use a solo cup sized container filled with soil or coco and place the seeds about 3/4 inch (~ 2cm) deep. Keep the medium moist but not wet until you see the seedlings emerge between 3 and seven days later. The reason we recommend peat moss over directly planting in soil is that it is easier to control moisture levels in peat plugs due to the texture and qualities of peat. Experienced growers often sew directly into the growing medium.

Many farmers use rock wool cubes for starting clones and germination, particularly hydroponic growers. While these work well and are economical, they come with drawbacks. We recommend that new growers begin with peat pellets.

How long does it take to germinate?

From the time that you place your seed into the germination medium, you should start to see the emerging seedling within 2-5 days. Cannabis seeds germinate faster when they are kept at the correct temperatures, between 70°F-80°F (21°C-26°C), with a 60-80% relative humidity. Cooler temperatures will slow the germination process or stop it altogether. Germination is usually complete, and the plant is a young seedling within seven days. If you warm the seedlings with a heat mat, they can emerge in as little as 24 hours.

Should I germinate with nutrients?

Germinating plants don’t need any nutrients; it can burn their new leaves and roots. That’s why it’s best to grow seeds in an inert medium, like peat moss pellets or a paper towel. Young seedlings don’t need nutrients until they are a few weeks old.

Do cannabis seeds need light to germinate?

Not really, but they need light within the first day or so of emerging from the seeds, so it’s a good idea to germinate with a light source. Light sources also help increase the temperature, helping the germination process. Sunlight, fluorescent or low powered LED grow lights are all great options.

What if the seed gets stuck on the seedling?

They usually loosen and come off after a day or two. If it doesn’t come off, you can try to separate them. The easiest method is to find the direction of the crack and use a pair of tweezers to ‘help’ the seed continue cracking. Be careful that you don’t clamp the seed down or you can clip the folded embryonic leaves.

Next up, read our seedling care guide to learn how to care for your new seedling.

Learn More

Seedling Guide

In this chapter, we’ll cover caring for your cannabis seedlings. The seedling phase begins when…
Read more