Growing Cannabis From Seeds Indoors

Learn how to sprout marijuana seeds with different germination methods from professional growers. We explain the best methods and the light cycle to use. Learn how to set up a grow room for marijuana, including adjusting the climate, air flow, grow lights, and watering and fertilization systems. Learn how to grow weed indoors with this step-by-step guide that'll teach you exactly how to turn a seed into a smokeable dried flower.

How to Sprout Cannabis Seeds | Growing Marijuana Seeds Indoors

If you want to grow weed, then there are two ways to start: with a clone or from seed. If you are starting with seeds, this article is for you. In this article, we explain what causes seeds germinate, and the best methods you can use to germinate your seeds and start the growing process.

What causes marijuana seeds to sprout?

Seeds normally sprout when subjected to warmth and humidity. In nature, this occurs when the seed falls from the plant during the winter months and goes underground. As the season changes to spring, the earth becomes warmer, which causes the seed to sprout.

When you are growing cannabis indoors, you must mimic these environmental conditions to get your seeds to sprout. But with all things related to cannabis cultivation, there is more than one way to skin a cat. There are so many different way to grow weed, and even when it comes down to popping seeds, there’s more than one way to do it.

How Long do Cannabis Seeds take to sprout roots?

It all depends on the temperature. The warmer and more humid the environment, the quicker they will sprout. When using the paper towel method along with some warming pads, it is possible for the seed to sprout within 24 hours. Most typically, it will take a seed at least 2 or 3 days.

If the seed is left at room temperature, it will take more like 5 or 6 days for the tap root to sprout.

Methods for Sprouting Cannabis Seeds Indoors

There are many ways to sprout marijuana seeds, and this article only covers a few. But once you understand the fundamentals of this concept, your imagine can come up with many more ways. This list contains the methods that we use, as well as some other known methods for popping beans, as they say.

Planting the Seed in Soil is the most basic method for sprouting marijuana seeds

The most basic method is to simply plant your seeds in soil. This could be indoors or outdoors. If outdoors, the seed will not sprout until the earth is consistently warm, which will be late spring or early summer, depending on where you live.

When planting seeds indoors, you will want your soil to be at least room temperature, if not warmer. After planting, you will wait a few days for the baby seedling to poke through the soil and rear its head.

The Paper Towel Method is tried and true way for sprouting cannabis seeds

To sprout our seeds for our pheno-hunt projects, we use the paper towel method. If you’ve never used this method, it basically entails dampening a paper towel, putting the seed in the middle and folding it over. You then place the wet paper towel in some Tupperware, put a lid on it, and put it in a drawer. Come back a day or so later, and check to see if the seed has sprouted a tail.

You can also use warming pads to help nurture the process. The warming pads can speed up the sprouting process. You simply place the seeds on the pad, put it in the Tupperware or in a drawer, and wait.

The benefit of the Paper Towel method is that it is probably the most forgiving. If you are new, try this method and let us know how it went.

You can plant the seed in Rockwool and wait for it to sprout

You don’t see this method used too often, but we know of growers who drop seeds directly into rockwool cubes. The methodology would be the same as planting a seed in soil. You would make sure to water the rockwool cube, and control the environment of the room so the temperature is warm up to heat the cube and cause the tap root to sprout.

You can cause a cannabis seed to sprout by dropping it in a cup of water

Another method that is fairly simply to do is to drop your seeds into a cup of warm water. You would simply wait a day and check it frequently to see if it sprouts.

The same rules apply. You want the water and the environmental temperature to be warm to encourage the tap root to sprout.

There is a downside to this method: You must monitor and be ready to act quickly. If the tap root does sprout, it can rot if left for too long in the water. So if you use this method, monitor it daily. Once you notice the sprouted tap root, remove the seed and plant it in soil.

What to do once your cannabis seeds have sprouted: Transplanting your Seedling

Once your seeds have sprouted, it is time to transplant them into soil. This is assuming you did not initially plant your seeds in soil.

If you initially planted your seeds, you do not need to transplant unless you planted them in a very small container, like a red solo cup. In that case, you will want to transfer them to a larger pot.

What size of pot you use will depend on how large you intend on letting the plants get while in vegetative stage.

What Light Cycle should you use with sprouted cannabis seedlings

Once you have transplanted your seedlings into a new pot with soil, you will want to place them under direct lighting. For young seedlings, use a softer light, such as a fluorescent light. You do not need all the lumens in HPS or even high powered LED.

For young marijuana seedlings, use the 18/6 light schedule. This is the same light cycle you will use for the entire vegetative period. Place the plants under direct light for 18 hours, and then let them sleep with the lights off for six hours.

Now, you are ready to veg your plants. Afterwards, you will put them through a bloom cycle. For more information on those two periods, check out our articles on Understanding the Vegetative Stage and the Flowering Stage of Marijuana Growth.

How to Grow Cannabis Indoors

In terms of temperature, remember this rule: No colder than 60, no hotter than 85, and never above 90.

Focus on air flow

  • Help to regulate heat and humidity: Grow lights kick out a lot of heat, which also increases the humidity in the grow room. An exhaust fan pulls hot and humid air out of the grow room, creating a vacuum that pulls in cooler, drier air (assuming the room has intake holes or vents).
  • Deliver CO2 to plants: Plants breathe in carbon dioxide (CO2) and breathe out oxygen (O2). Without proper ventilation, the CO2 supply in the room is depleted, and the plants “suffocate.”
  • Prevent pests and diseases: Warm, humid, stagnant air provides an ideal environment for mold, mildew, fungi, and certain pests. Pulling in cooler, drier air eliminates this problem, and having a breeze in the room helps to discourage infestations of small flying insects such as gnats.
  • Strengthen plant stalks and stems: Plants sense the breeze in the room and grow hardier as a result, which provides more support for buds during the flower stage.

Improper air flow in grow rooms is the number one reason for reduced yields and complete crop failure.

Ensure proper ventilation

The first order of business is to install one or two fans to ventilate the room — an exhaust fan, an intake fan, or both. With an active system, you have an exhaust fan on one end of the room and an intake fan of the same size on the opposite end. In a passive system, you use only one fan. As the exhaust fan pulls air out of the room or the intake fan pushes air into the room, air flows in or out through one or more holes on the opposite end of the room. In passive systems, the hole (or holes) without the fan must be larger than the hole with the fan.

Most grow rooms use in-line duct fans, which are very easy to install. Installation is similar to connecting a flexible duct pipe to a clothes dryer. You can buy 4-, 6-, or 8-inch diameter in-line duct fans depending on the size of the room and the size of any existing holes. Six-inch fans are common. If you have a grow tent, check the size of the exhaust and intake holes and buy fans to match.

Also check the cubic feet per minute (CFM) rating of the fan(s) and buy a fan with a CFM rating that’s higher than the volume of the room in cubic feet. The general idea is that you want sufficient ventilation to completely replace the air in the grow room once every minute. Simply measure the room’s length, width, and height in feet and multiply the three numbers. For example, if the room is 3-by-3-by-6 feet, 3 × 3 × 6 = 54 cubic feet, so a fan with a rating of 100 CFM would be sufficient. However, you may need a fan with a higher CFM rating if you’re pumping the air over a long distance or have one or more bends in the duct pipe.

Your intake hole should be near the bottom at one end of the room with the exhaust hole at the top of the opposite end of the room. The exhaust hole is higher, because heat naturally rises to the top.

Whether you use one or two fans, install a filter on the intake and exhaust ducts. The intake filter keeps out bugs, mold spores, dust, and other contaminants. The exhaust filter is usually a carbon filter that helps to reduce the odors from the cannabis exiting the room. You attach the filters directly to the fans or use a piece of flexible duct pipe between the fan and filter.

Use as little duct pipe as necessary and run it as straight as possible. The longer the distance the air has to travel and the more bends in the pipe, the less efficient the air flow. If you must run pipe a long distance or add a bend, consider buying fans with higher CFM ratings.

Circulate the air

Air circulation is also important. Plants don’t “exhale” with any type of force during respiration. Fans used to circulate the air move the O2 surrounding the plants and replace it with CO2 that the plants can “breathe in.” You need one or more fans inside your grow room to maintain proper circulation. Deciding on the number of fans and positioning them in the room is mostly a process of trial and error. The goal is to have all parts of all plants “dancing” — all the leaves should be shaking gently. If you notice any part of any plant that’s not dancing, you may need to reposition the fan(s) or add a fan.

Start with two small fans in opposite corners of the room or one slightly larger oscillating fan in one corner of the room and make adjustments from there.

Supply carbon dioxide

Plants require CO2 to survive. This is the symbiotic relationship plants have with animals. Animals breath in O2 and exhale CO2; plants “inhale” CO2 and “exhale” O2. If your grow room has adequate air flow, CO2 sublimation isn’t necessary, but it increases overall yields if you’re using higher intensity lighting.

Several methods are available for adding CO2 to a grow room. You can buy a tank of CO2 and simply pump it into the room, allow dry ice to melt inside the room, or buy CO2 canisters or bags that release the gas slowly into the room over a period of time. If you’re adding CO2 to your grow room, keep the following important points in mind:

  • Add CO2 only when the lights are on. When the lights are off, plants slow down their use of CO2 considerably, so any CO2 added is CO2
  • Turn off the intake and exhaust fans for a few minutes when releasing CO2; otherwise, you’re pumping out the gas, and wasting it.
  • Add CO2 from the top of the room and in front of one of your circulating fans. It’s denser than air, so it tends to drop toward the floor. For example, if you’re using a CO2 tank, run a hose to near the top of the grow room and lower it so it’s in front of one of the fans.
  • Maintain a level of 900 parts per million (ppm) of CO2 during the vegetative stage and 1,150 ppm during the flower stage. You’ll need a CO2 meter to monitor CO2
See also  What Does A Female Cannabis Seed Look Like

Additional CO2 is necessary with higher light intensity, enabling the plant to take advantage of the added light with greater photosynthesis.

Set up grow lights

Lighting is a key factor in a successful indoor grow operation. The types of lights, the way you set them up, and other pieces that control and direct them are the keys to your yield and the flavor of your end product. Here, we guide you through the process of choosing and installing your grow lights.

Calculate your lighting needs

Before you head out to your local nursery or hardware store to shop for grow lights figure out how much light you need. In general, a standard 1,000 watt grow light will cover four plants that have a fully grown diameter of about 3 feet, depending on strain. If you set up your grow lights and plants and notice that some parts of one or more plants aren’t receiving light, you’ll need to add one or more lights.

Choose light fixtures and bulbs

Most standard household light fixtures and bulbs are insufficient for growing cannabis. They don’t provide the intensity and quality of light the plants need for optimal growth. The exception is fluorescent lights (typically T5s) or compact fluorescent lights (CFLs), which are okay, but result in smaller, lower-quality buds. We don’t recommend fluorescent lighting.

After ruling out fluorescent lighting, your choice of grow lights depends on your goal and the stage of growth:

  • If your goal is high yields, choose a high intensity discharge (HID) bulb — metal-halide (MH) for the vegetative stage and high-pressure sodium (HPS) during the flower stage. These bulbs emit a lot of light and a lot of heat, so you need to position them at a greater distance from the plants.
  • If you’re looking for better terpene yields for extraction, use light-emitting diode (LED) or ceramic metal halide (CMH) bulbs, because these preserve the terpenes without bulking up the flower weight and density the way high-intensity discharge (HID) lighting does.
  • Fixture with reflector hood: The fixture holds the bulbs, and the reflector hood directs the light down to the plants. Reflector hoods come in different types:
  • Closed hood: Shaped like a box, a closed hood reflector creates a more focused beam of light (and heat).
  • Vented hood: Similar to a closed hood reflector but with openings on the ends for connecting the hood to in-line duct fans for cooling.
  • Wing: Typically a curved and textured aluminum sheet that provides a less focused beam of light than a closed hood reflector. The light covers a greater area but is less intense (so is the heat).
  • Parabolic: Shaped like an umbrella, a parabolic hood distributes light like a wing but in a more circular pattern.

Your choice of hoods is a personal preference. Go with a closed hood if you’re concerned about heat or with an wing or parabolic if you’re not.

  • Ballast: The ballast provides control over the current that the lightbulb draws from the power source. The following two types of ballasts are most common:
  • Magnetic: Less expensive, heavy, hot, potentially noisy, susceptible to flicker, and supports only bulbs of a certain wattage. If you want to change from a 400W bulb to a 600W bulb, for example, you need to replace the ballast.
  • Digital: More expensive, smaller, lighter, cooler, quieter, less susceptible to flicker, more efficient, may be equipped with a dimmable option, may cause radio frequency interference.
  • Hooks and pulleys: Grow light systems often include hooks and pulleys for hanging the light fixtures in your grow room. Pulleys enable you to more easily raise and lower the light fixtures to place them at the right distance from the tops of the plants.
  • Timer: Grow light systems typically come with a timer, or you can purchase a timer separately, which automates the process of cycling the lights on and off on schedule.

Mount your light fixtures

Mount the light fixtures to the ceiling of the grow room above the plants, positioning the fixtures to ensure equal distribution of light over the entire canopy. How you mount the light fixtures depends on the fixture and how your grow room ceiling is configured. Using hooks, ropes, or chains and possibly pulleys, you can hang your fixtures in a way that you can easily raise and lower them to the proper distance from the tops of your plants.

Position the lights above the plants, so all parts of all plants are receiving light. The light should be as close to the top of the tallest plant as possible without burning it. Keep a close eye on the plants whenever adjusting the lights, and if the top of any plant is getting burned, raise the light.

Don’t place anything flammable close enough to the light that there’s any possibility the light will ignite it.

Set and reset timers

During the vegetative stage, plants require 18 to 24 hours of light. During the bloom/flower stage, they need 10 to 12 hours of light and at least 12 hours of total darkness (for photoperiod strains); auto-flowering strains will flower without 12 hours of darkness. Putting your grow lights on timers greatly simplifies the process of managing the required light/dark cycles, but you still need to manage the changes in lighting over the growth cycle.

If you plan to have a continuous garden with some plants in veg and some in bloom, set up your lighting differently in those two areas. For photoperiod strains, use a separate grow tent or grow room for plants that are in the vegetative stage and those that are in the flower stage.

  1. Position the lights at the proper distance above the canopy for the vegetative stage.
  2. Adjust your light timer(s) to provide 18 to 24 hours of light. Experiment with different settings in that range over several grows to find the optimum amount of light for each strain you grow.
  3. Keep an eye on your plants, adjusting the lighting as necessary to keep the lights the proper distance from the tops of the plants as they grow taller.

When your plants are about half the size of full-grown plants, they’re ready to switch from the vegetative to the flower stage. (At this point, you either adjust the lighting, as explained in the remaining steps or move the plants to the flower tent or room.)

The size of a full-grown plant is strain dependent and impacted by light, container size, and other environmental influencers such as CO2. You may have to go through several rounds of growing a particular strain to develop a clear idea what the size of a full-grown plant is and when the plant is ready to switch from the vegetative to the flower stage.

You don’t need to change out fluorescent, CFL, or LED bulbs.

When changing to the brighter HPS bulbs, shade the plants for a couple days to prevent them from getting blasted by the more intense light. You can place a piece of cardboard between the light and the plants to serve this purpose, but make sure it’s as far as possible from the light to prevent a fire.

Measure the light

Light intensity has a big impact on yield. All parts of all plants should have exposure to the light, and the lights should be as close to the plants as possible without burning them. If the top of any plants are wilting or burnt from the light, raise the lights.

For more sophisticated grows, obtain a photosynthetic active radiation (PAR) meter and take measurements at several different locations above the canopy to measure the PAR output of the lights. The PAR measure should never rise above 1,200 PAR.

Decide on a watering/fertilizing system

Whether you’re growing indoors or outdoors, you need to decide on a system for watering and fertilizing your plants. You basically have two options: manual and automatic. During your first grows, we recommend the manual method as you develop a sense of how much water and fertilizer your plants generally need.

After developing an understanding of your plants’ water and nutrient needs (which may vary depending on the strain), consider installing an automated irrigation system. These systems are equipped with timers that water and feed plants automatically on a pre-set schedule. They provide the same benefits of lighting systems — the convenience and reliability of automation. However, you still need to monitor your plants to be sure they’re getting enough and not too much water and nutrients.

Use a hydroponics system

  • Aeroponic: Plants sit in a tray above a water/nutrient reservoir with their roots dangling down. Solution from the reservoir is sprayed up onto the roots at regular intervals, and excess solution drips down into the reservoir.
  • Drip: Nutrient-rich water is dripped slowly at regular intervals into the grow medium where the roots can absorb it. Unused water drains back to the reservoir to be reused or to a waste reservoir and then discarded.
  • Deep water culture (DWC): Plants sit in baskets above an aerated (and typically chilled) water/nutrient reservoir with their roots submerged in the solution, which allows for continuous feeding.
  • Ebb and flow: Plants sit in pots in a grow tray. Nutrient-rich water is pumped into the grow tray at regular intervals and flows into holes at the bottom and sides of the pots. The pumping stops and water is allowed to drain back into the reservoir from which it was pumped.
  • Nutrient film technique (NFT): NFT is like a cross between DWC and ebb and flow. Plants sit in baskets above a grow tray. Nutrient-rich water is continuously pumped from a reservoir into the grow tray and then drains from the opposite end of the grow tray back into the reservoir. This arrangement delivers a continuous flow of nutrient-rich water to the roots.
  • Wick: A plant sits in a container above an aerated, nutrient-rich water reservoir, and a rope or other absorbent material (such as felt) is placed through the middle of the growth medium and into the reservoir. Through capillary action, the solution from the reservoir “climbs” the rope, providing the plant with as much or as little water and nutrients as it demands.

Here are a few suggestions for increasing your odds of a successful hydroponics grow:

  • Disinfect all your hydroponics equipment with isopropyl alcohol or bleach between grows to kill off any bacteria or other infectious agents. Anaerobic bacteria can build up in dirty systems and kill your plants from the roots up.
  • Use clean, pH neutral water. Water from a reverse osmosis (RO) system or distilled water is suitable.
  • Aerate the nutrient-rich water solution. You can place an aeration stone in the bottom of the reservoir attached to a small air pump like those carried by local pet stores. Without aeration, your plants may not receive the oxygen they need.
  • Replace the water/nutrient solution every couple weeks. Don’t merely add nutrients, because nutrient concentrations may become too high as a result. (Remember to use a fertilizer with a higher nitrogen concentration during the vegetative stage and higher potassium and phosphorous during the flower stage.)
  • After dumping the old nutrient solution, run a dilute water and hydrogen peroxide solution through the system to clear out any infectious agents and then rinse with plain water.
  • Consider flushing the grow medium with plain water whenever you change the nutrient solution.

When choosing and setting up a hydroponics system, research to find out the type of system that’s best for your grow space and skill level. Simpler is usually better. Use high quality food grade plastics in your system and make sure it’s leak free before starting your grow.

Keep your grow room impeccably clean

  • After each use, wash and disinfect plant containers, grow trays, irrigation hoses, and pumps. Use soap and water followed by isopropyl alcohol or a bleach solution (one part bleach to three parts water). Then, carefully rinse everything with plain water.
  • Keep your grow room free of any dead plant mater and debris. This is where many pests and pathogens can get a foothold in a garden of healthy plants.
  • Watch for common pests such as aphids, fungus gnats, spider mites, and thrips. If you see even one of these nasty critters, identify it and find an effective pesticide. This is where your friendly garden store or grow store staff comes in handy.

About This Article

This article is from the book:

About the book authors:

Kim Ronkin Casey has been a communications professional for more than 20 years and recently took a year-long leap into the world of cannabis as the communications manager for one of the leading dispensaries in North America. She now consults for companies in the industry on internal and external communications. Joe Kraynak is a professional writer who has contributed to numerous For Dummies books.

How to Grow Weed Indoors [Beginner-Friendly Guide]

I’m here to tell you that growing weed indoors step-by-step is easy. Just follow along.

Because it’s the first choice of thousands of beginner growers, I’ve decided to put together the most comprehensive soil weed growing guide on the internet.

In this guide, we will go through the whole growing process, from choosing the seeds and soil to harvesting and curing the buds. Hopefully, by the end of this guide your cannabis growing knowledge will grow as much as your plant.


Preparation stage

The first week (or week 0 as I like to call it) is when you prepare your grow.

It doesn’t necessarily have to be a whole week, however it can often be longer.

You might think:

“So, it’s not a week at all?”

And you’d be right.

You won’t be doing any growing this week as you can’t grow plants without the seeds first.

Week 0 is focused around finding the best soil, seeds, lights and setting up your growing tent.

Even if you are growing hydroponic marijuana you have to do the prep stage, which might be even longer for hydroponic setups.


For this indoor soil growing guide we will use one of the most popular strains ever: White Widow.

But, we won’t use just any White Widow.

For this occasion we will use the autoflowering version of this plant.

Well, for a few simple reasons:

Autoflowering plants are smaller, but they don’t cut down on the yield, they are easier to grow, and they grow faster than regular plants.

You will want only feminized seeds for this grow as male plants do not grow flowers.

“Your plant is only as good as your soil.”

I find this to be one of the biggest truths of growing cannabis.

Beginner growers often experience problems with their soil, such as malnutrition and over-watering.

Both of these will have a long term effect on your plant if not dealt with in the quickest manner.

This is not to say that cannabis won’t grow in slightly bad conditions, far from that.

It’s called “weed” for a reason. It will grow even in sub-par conditions, however the end result might not be what you hoped for.

So, in order to avoid any confusion, do your best to get the perfect soil, and if you fail, you can still make it up by adding nutrients.

Feel free to buy any of the branded soil mixes, except for those that are labeled “extended release”as they will release nitrogen to your plant roots for up to 6 months, meaning that you will have n0 control over the pH levels of your soil.

The best option out there for first-time growers is “Super Soil”, a special mix of soil that can be found in stores. KindSoil is one of the more popular brands of Super Soil.

With any Super Soil mix you won’t have to add any nutrients, as the mix comes premade, so water will be the only thing you add to it—by watering the plants.

Fun fact:

Did you know that earthworms in soil can increase the yield up to 75%? According to scientists from Netherlands, earthworms might be one of the most important parts of a soil-based grow.

However, this study was done on wheat plants so I wouldn’t suggest you throwing earthworms in the mix if you haven’t had at least a dozen successful grows.

Lighting setup

Lights are super important for growing cannabis and insufficient lighting is one of the biggest reasons why many indoor grows fail.

Lighting depends totally on the size of your grow.

Basically there are 2 most common options for lighting:

  • LEDs
  • CFLs (Compact Fluorescent Lights).

CFLs give off more heat than LEDs and are better suited for growing in small spaces, such as tents.

Their downside is that they tend to spend more energy and you will have to readjust them more often than LEDs.

So, my end recommendation is this: if you have room for LEDs and you are willing to go through the hustle of setting up LEDs, be my guest.

For a small first time grow, I would suggest getting a CFL setup with lights up to 300W.

Keeping CFLs close to the plants will bring in the best yields and ensure the biggest plant growth.

The tent

Growing tents are perfect for those that tend to grow in their garage or colder areas of the house, as the tent holds the warmth within itself, helping plants get bigger as soon as possible.

If you plan on growing marijuana in a closet, or a similar closed space that doesn’t let too much heat out, I would suggest that you approach it with caution.

Either way, the most important thing is to keep the temperature at a constant 25°C (77℉).

In case you do go with a tent, you will have to extract the air from the tent, which is removed using a fan that sucks the air out through tubes.

Most modern tents have a carbon filter which prevents the smell of weed leaving the tent, so keep that in mind when shopping for one.

If you still think you can make do without a tent, then get ready to spend some money on fans and/or ventilation systems.

Most modern air extractor fans include temperature and moisture controllers, which will come very handy when calculating your VPD (we’ll get to that later), so I strongly suggest you get one of those.

Pro tip: if you have cats you are going to want to get a tent. Just trust me on this one. I’m saving you money, effort and a lot of nerves.

Light schedule for growing weed indoors

Light periods for autoflowering plants are really easy to grasp:

All you have to do is keep the light turned on.

Like, all the time.

I am not joking when I say that you should keep the lights on 24/7.

Giving 24 hours of light is crucial when growing autoflowering plants, as it may give them the best chance to grow bigger in the vegetative stage and then eventually flower when their time comes.

Autoflowering plants do not need darkness.

Autoflowering plants are not dependent on changes in the light cycle to commence flowering.

This is why they can be grown using a light cycle of anything from 16 to 24 hours daily.

This is also what makes them perfect for first time growers as light periods are one less thing to worry about.

Germination & seedling stage

Time to put those girls into action!

But first, some more prep.

VPD for weed

Creating the perfect environment for your plants doesn’t necessarily end with buying all the right gear.

You will have to know how to properly set it up, and more importantly, how to make the perfect atmosphere for your plants to grow to their potential.

Dehumidifiers decrease environmental moisture and release heat, which can be helpful in certain cases like very moist and cool areas, such as basements.

If you want know how to grow big buds indoors, you have to understand the importance of VPD.

Whether you are growing weed in a closet or a tent, you will have to control the atmosphere.

Humidity is one of the more important factors to control and this is in part due to the fact that different humidity levels are best for different growing stages.

In general, the air humidity for growing weed indoors is as follows:

One thing which is closely connected to air humidity is VPD.

VPD stands for Vapor Pressure Deficit, and it represents the difference between the pressure of water vapor in 100% saturated air at a certain temperature (leaf’s vapor pressure) and actual vapor pressure in the air surrounding the plant.

Plants with higher VPD values will generally have a higher transpiration rate and increased nutrient movement.

Germinating weed seeds

Learning how to germinate a weed seed is a piece of cake, and also the first step you will take towards your new hobby.

Germinating seeds is a process of forcing them to begin to grow and put out roots.

Seeds can be germinated in many ways and the first time you do it you will get a hang for it because there isn’t really too much science behind it.

How to germinate weed seeds?

There are several ways to do this.

Germinating seeds in soil

Germinating seeds in soil is the easiest way to do it because all you have to do is toss them in your pot, cover with some dirt and douse with water.

You only need the soil to be damp so make sure you do not over water it. You can use clear kitchen plastic to wrap the tops of the pots to maintain humidity. Keep the pots in a warm area.

Germinating seeds in water

Germinating seeds in water requires even less effort than germinating seeds in soil.

You literally just have to throw them in a cup of water for 14-18 hours.

One thing that makes this way better than germinating in soil is that you can see if a seed is bad by checking if it didn’t sink. Those that sink are good.

After the seeds start rooting, move them on a damp paper towel and cover with another damp paper towel.

Place the paper towel covered seeds in a dark area and they will grow roots in a matter of days.

After that, all you have to do is move them into a pot.

Germinating seeds with paper towels

For this method, you take a couple of seeds, put them on a damp paper towel and cover with another one, after which you store them somewhere dark.

After a few days you should see roots embedded in the paper towels.

You can do this with gauze and cotton wool as well.

Seedling stage

Seedling stage begins once you’ve moved your seeds from the paper towel into the pot and you start seeing the first leaves break out from the ground.

Here’s a photo of a plant a few days into its seedling stage:

That is exactly what your plant will look like maybe a week after you’ve moved the seeds into the pots.

You don’t really have to do much during the seedling stage.

You don’t even have to water the plants too much as you’ll want the soil to be a bit dry so that the roots can catch better.

You might be thinking, “This man is crazy!”, and you’d be right.

But, letting your plant root strong is a great idea during the seedling stage, just make sure you don’t over water and suffocate the plant.

Over-watering is one of the biggest mistakes you can make, but we’ll get to that in a bit.

One of the most important things to remember for the seedling stage is that you will want to move your plants in a bigger pot as soon as you see the first few leafs show.

Knowing how and when to transplant your plants is perhaps the best knowledge we can pass onto new growers, as leaving plants in small pots can choke them up, while moving them too early can have terrible effects, especially if you don’t do it right.

Further along the road you will most likely have to re-pot the plants again.

I strongly suggest you move the plants as soon as you see the first leaves appear.

The second re-potting should happen once your plants have rooted in firmly and appear ready to be moved—this means that the plant looks stable enough to be moved.

Whatever you decide to do regarding re-potting, keep one thing in mind: The less root damage the better.

Vegetative stage

Vegetative stage starts when you see that the plant is looking more like a weed plant than just a regular plant, meaning that it has clear weed-like characteristics.

You will start seeing the recognizable fan leaves and many branches stemming from the trunk, alongside that familiar skunky smell.

Vegetative stage starts roughly around the second week for most autoflowering plants, but for others it might start in the third week.

Either way, once your plant starts growing in size by the day you will know that you successfully reached the vegetative stage.

Watering weed plants

Watering weed plants is a tricky business if you’ve never watered plants in your life.

Most growers water their plants from the tap so there aren’t really any reasons why you shouldn’t do the same.

The amount of water you will use for your plants varies depending on the specifics of your grow and the environment in which you hold the plants.

It also depends on the size of the plant, air temperature, soil composition, water quality and the capacity of your air filtration systems.

However, seeing how this is intended for beginner growers we won’t go in depth too much with watering.

Let me just leave it at these 3 things:

  1. Water whenever you feel that the top of the soil is dry
  2. Bigger pots — water less often, smaller pots — water more often
  3. Make sure you have appropriate drainage (to avoid overwatering)

Pro tip: Get yourself a bottle of carbonated water, and sprinkle the weed leaves. Carbonated water has CO2, which your plants crave.

How to clone weed plants

Similarly to re-vegging autoflowering weed strains, cloning them is extremely hard or next to impossible to do.

This is due to the fact that autoflowering strains have grown in the northern areas of the planet in which they had limited time to flower.

Cloning an autoflowering seed will create a plant of the same age as the mother plant.

Clones share the exact same genetics as the mother plant, which includes their age.

So, if this is your first grow, chances are that you won’t even try cloning a plant.

If you’re growing a photosensitive strain, however, cloning should be a piece of cake.

  1. Contrary to popular opinion, don’t cut off the most bottom node. Cut at least the 2nd or 3rd node.
  2. Fill a solo cup with soil and punch a hole on the top of the soil about 10 cm deep.
  3. Shave off a bit of the skin on the bottom of the cutting so it can form roots more easily.
  4. Stick the freshly cut branch in the hole you just punched and water your new plant.

Cloning weed plants is a great way to save money and keep growing the same plant with great genetics over and over again. You can clone one plant as many times as you want, and the clone of that clone.

Hell, cloning works even with cats.

Flowering stage

Once your plants reach a decent height and size it is time to flower.

Since we are growing an autoflowering strain, you won’t have to put any effort into changing the light schedule or anything.

Once your plant feels the time is right, it will start flowering.

How to know if your plant is male or female?

“Feminized cannabis seeds are bred to contain no male chromosomes, thus ensuring that every plant grown from them will flower as a female and be able to produce the crop of resinous buds sought by most growers”.

But, what happens if you buy random seeds which aren’t feminized?

Well, in that case you will simply have to sprout all the seeds, and wait for them to grow up a bit.

There are some general rules that will help you determine the sex of your weed plant:

  1. Male plants mature faster, most of the time about two weeks before females;
  2. Male plants also have “false buds” which are actually pollen sacs;
  3. Male plants have flowers while females still have pistils at this point.

It is important to keep in mind that cannabis plants can also be hermaphrodites, which means that one plant has both male and female traits.

Pro tip: It is very important that you keep male and female plants separate (or toss the male plants away) as there is a chance that male plants might ruin your grow by fertilizing the female plants.

Post-harvest stage

Most autoflowering plants will show best results around the 11th or 12th week, which is usually a great time to harvest.

But, before you cut your flowers and start drying, here are 2 things to know before you throw away the remaining pieces of the plant:

  • Harvested plants can grow again and bring more crops (unless they are autoflowering strains) by re-vegging the plant;
  • You can still clone the plant that you just cut up as long as there are healthy leaves.

Make sure that you don’t rush too much with harvesting, as cannabis needs time to develop higher levels of THC, so harvesting a bit later is a lot better than harvesting too soon.

How to re-veg weed plants

To reveg a weed plant means to send it back to the vegetative phase right after the harvest.

Now, I know I said that we will be using an autoflowering seed for this, and the common knowledge is that autoflowering plants cannot be re-vegged.

However, let us pretend again for a minute that we started with a photosensitive seed, in order to show you how re-vegging works.

You might wonder:

“Why reveg weed when you’ve already harvested the plant?”

There are multiple answers to this question:

  • If you had a great yield and you want to repeat the same results;
  • If you don’t want to spend money on new seeds;
  • If you want the same genetics but different results.

So, in order to re-veg the plants you will first have to harvest it.

  1. Cut off all the bigger branches and just leave the trunk of the plant snapped with a few of the smaller branches remaining
  2. Those smaller branches should have a few flowers on them. From these flowers you will see new leafs appear and grow once the plant starts to re-veg
  3. Put the plant back into the growing room and give it 18 hours of light.

You will see new branches appear from the old flowers and once it hits a decent size, put it back to 12 hours of light and 12 hours of dark so that it may flower.

Most plants that get re-vegged will start growing in a bushy manner rather than straight up as they used to.

This is a slow process so don’t be hasty and take your time taking care of the plant as it is a hard process for the plant as well.

How to dry weed

There are 2 things to keep in mind when drying weed:

  1. The room has to have a certain level of humidity, which is around 50%-60%;
  2. The optimal temperature for your drying room is 21°C (70°F).

For best results, you should dry your buds slowly over the course of 3-7 days.

The drying time depends heavily on the climate in your area. In high-humidity climates the drying process will likely last longer, and vice versa.

Experienced smokers know how a properly dried bud feels in the hand, so if you are not certain don’t be afraid to ask.

Here are a few rules to keep in mind when you’re drying buds:

  1. Keep the area clean and dust-free;
  2. Control humidity and temperature (50%-60% and 70°F or 21°C);
  3. Remove the big leaves and hang the pruned colas and buds upside down on a clothing line or wire;
  4. Keep them properly spaced out, especially in relatively humid drying rooms;
  5. Move the nugs to the curing jars once the twigs start snapping.

Once you’ve moved your buds to the curing jars, the curing process begins.

If you wanna read in depth about drying weed, click here for our full article on how to dry weed.

How to cure weed

Curing marijuana buds is the last step in producing a smokable flower. After curing, your weed will have a much more impressive smell and taste.

Here are some of those big truths about properly drying and curing marijuana:

  • This process breaks down chlorophyll and improves taste and smoothness of the smoke;
  • It will bring out the specifics of your strain when done right, such as the smell and fine flavors;
  • Less chances of mold appearing on your buds.

Check out the photo below for a comparison of well dried and cured weed and poorly dried and cured weed.

Here’s a 5 step tutorial on how to cure weed:

  1. Trim off the smaller leaves and stems that you find remaining after the drying process;
  2. Place the buds in an airtight mason jar, but make sure you don’t cram them up inside. They need some space to cure properly;
  3. Place the jars in a cool, dark place, and make sure there is no sunlight as it breaks down cannabinoids. Make sure you take off the lids every day for 60 minutes to get the fresh air in;
  4. Control the temperature (around 70° Fahrenheit or 20° Celsius) and humidity in the jars around 60% by using humidity packs;
  5. Cure your buds for at least 4 weeks to get the optimal potency and taste, and if you aren’t in a rush you can cure for 6-8 weeks for high-grade buds.

Many people have used small refrigerators for curing weed, as it is fairly easy to control the environment within with heat and humidity packs.

Curing weed in a fridge might be a great way to start if you’ve never done it before.

It is easy, it is convenient as little to no smell is left behind, and there is no way the light will come in.

Go wild

Now it’s up to you to get started and go wild.

Growing weed can be a great hobby for all those that have enough time and passion for smoking cannabis.

Young adults do it all over the US and Canada, just as much as retired folks because it doesn’t require much to be good at it.

Experience is perhaps the biggest factor in growing weed, so don’t be surprised if your first crop doesn’t yield much or the buds don’t look like the ones you buy in a medical dispensary.

These things depend on just about everything, from the strain you are growing to lamps that you use and how long you dried and cured buds after harvesting them.

If you ever get stuck, or things start going south (leaves going yellow, mites problems, etc.) don’t be afraid to ask for help. There are people out there just waiting to hear your problems and see your plants. Many Facebook groups are named “Growers helping growers” so it might be a great idea to join one, just in case you need advice and assistance over the course of your grow.

See also  Cannabis Seed Development