How to grow Cannabis in a Closet Part 2: Seedlings

// October 22, 2017

Once your cannabis plant has sprouted through the soil, it is a seedling and has entered the vegetative growth stage. During this stage, the plant will develop a strong root system, assume a gender, grow its stems and leaves, and reach flowering maturity. The best crops start out with two key features: good genetics and unrestricted growth. Therefore your job will be to (1) nurture the seedling with adequate soil, water, and lighting while it grows, and (2) raise enough seedlings that you can cull any males and keep only the healthiest of the remaining females, raising those chosen few to full maturity.

This guide will teach you how to grow four plants, one meter in height, in a closet space of about 1 meter squared. If you would like a definitive guide on how to grow cannabis in all quantities and environments, check out or buy Jorge Cervantes’ The Cannabis Encyclopedia.

Materials needed:

  • Cannabis Seedlings in 4″ pots
  • Wardrobe Closet
  • 1000W  LED Grow Light ($155)
  • Aluminum Foil ($5)
  • Fan ($20)
  • Power Bar ($20)
  • Plastic Bin ($20)
  • Soil ($20)
  • 3-1-2 Fertilizer ($10)

Assuming you have a wardrobe closet and seedlings already, these materials will cost you about $250 total if bought from Amazon. If you’re a student, you can sign up for Amazon prime for free and get 2-day shipping on most of the required items.

Step 1: Set up your Closet

Put your plastic bin on the ground and hook up your light to the ceiling. Next, cover the walls in tin foil so that excess light gets reflected down onto the plants. If you get a 600-1000W LED like the one I recommended, make sure that it is positioned at least one meter above your plants. This will encourage them to grow taller. Since you have more vertical real-estate than horizontal, this is a good thing. You can hang your light from a clothing dowel as in the picture, or screw a hook and caribeener system to the ceiling.

After you have set up your closet, you can put your seedlings in rows on top of an upside-down bin. Raise as many seedlings as possible at this stage so that you can select only the strongest ones when it comes time.

2: Day-to-Day Care

For small indoor grows, the fertilizer should be high in nitrogen. Don’t worry too much about phosphorus and potassium at this stage. For a quick indoor grow, it is better to start with a good soil and adequate nitrogen. Phosphorus and potassium will play a bigger part in the flowering stage.

You should be giving your seedlings a light cycle of 18 hours daylight, 6 hours of night, though for the first couple weeks it doesn’t matter as long as they get at least 18. You can have your light on 24 hours a day and your plants will grow.

Keep your soil moist, watering the plants in the morning, but make sure not to overwater. This will leech nutrients from the soil and prevent healthy root development. A healthy root is always seeking bigger, better water sources. So if you want the best growth, you can even try watering more on the sides of the pot.

One common problem which occurs during the early stage of vegetative growth is that the seedlings will fall over. They will start growing up, reaching for the light, but they won’t be able to support themselves. This can be corrected by blowing a fan on them to strengthen their stems. If they need support, get a small metal wire/bread tie, stick it in the ground, and lean the seedling to it. Make sure the seedling isn’t leaning too hard on it, or it won’t be encouraged to strengthen its own stem. After a few days it should be erect again.

3: Culling the Herd

Comparing a healthy seedling (left) with an unhealthy one (right)

Once your seedlings have become root-bound, it is time to transplant them into larger pots. I recommend using one large 15-25 gallon plastic storage bin for 4 plants, or one 3 gallon pot for each plant. Select the plants that have the healthiest root system and leaves, and plant the rest outside or give them to friends. Don’t get overly sentimental about seedlings that didn’t fare so well; you want to focus your precious time and energy on creating fewer, healthier plants.

In this image are some 3-week old seedlings from weakest to strongest.

4: Transplanting

To put your seedlings into a bin or pot, first you’ll have to give them a fungicidal/miticidal bath. A cheap way to do this at home is to mix a solution of 10% vinegar and  90% water into a bucket or cooking pot. Then, remove your seedlings from their styrofoam or plastic containers (or keep them in if you’re using degradable ones, like I am, dunk them in the solution for a second, then put them into the container so that the top of the soil reaches about 1-2 inches below the top edge of the container. Make sure to bust up the bottom roots a little bit and get the soil extra wet

Your seedlings will have experienced a lot of stress during this stage, so they may seem to stop growing for a couple of days. They’re okay. Keep their soil moist, and keep air circulating through your closet with a small fan.

4 out of 11 seedlings made the cut for Vegetative Growth

In the next article,  I will cover advanced vegetative growth: how to train/bend your plants to fit comfortably in your closet space and receive maximum lighting. I will also describe certain problems that may occur during growth, like mildew or nutrient excesses/deficiencies.

Thanks for reading! Comment below with any questions and I get back to you.