Cannabis plants go through a series of stages as they grow and mature, and those different growth stages call for different amounts of light, nutrients, and water.
If you’re growing weed indoors, you can grow whenever you like. Keep in mind that the outside environment will affect your grow space—you may need to add heaters in the winter or fans and ACs in the summer. Other than that, you can start seeds whenever you like and flip them into flower whenever you like, depending on how big you want the plants.
How long does it take to grow a marijuana plant?
As roots develop, the stalk will rise and you’ll begin to see the first iconic fan leaves grow, at which point your cannabis plant can be considered a seedling.
Once your seed has germinated, or sprouted, it’s ready to be placed in a growing medium, like soil. The tap root will drive down while the stem of the seedling will grow upward.
When your marijuana plant becomes a seedling, you’ll notice it developing more of the traditional cannabis fan leaves. As a sprout, the seed will initially produce leaves with only one ridged blade. Once new growth develops, the leaves will develop more blades (3, 5, 7, etc.). A mature cannabis plant will have between 5 or 7 blades per leaf, but some plants may have more.
To create a dark, protected space, take another plate and flip it over to cover the seeds, like a dome.
You might also find a mature seed that has been physically damaged through poor handling, like rough trimming. In those cases, it probably isn’t worth the effort to try and germinate the seed.
Autoflowering seeds are also popular with beginning growers. They are easy to grow because you don’t have to worry about light cycles and how much light a plant receives.
As interest in CBD as a medicine has grown, many breeders have crossed high-CBD hemp with cannabis. These strains have little or no THC, 1:1 ratios of THC and CBD, or some have a high-THC content along with significant amounts of CBD (3% or more).
Cannabis plant sex organs appear on nodes, the points where branches grow off from the main stalk.
After completing these steps, it’s time to wait. Check the paper towels once a day to make sure they’re still saturated, and if they are losing moisture, apply more water to keep the seeds happy.
For the typical homegrower, it may be easier to obtain cannabis seeds rather than clones. Growing from seed can produce a stronger plant with more solid genetics.
Environmental conditions are essential to growing healthy cannabis seedlings, and some of the most important conditions to control are temperature and humidity.
A nutrient deficiency can cause serious issues for your growing plant, so part of proper care is knowing how to spot the signs of a nutrient deficiency.
Choosing the right pot is an essential part of caring for your growing plant. Photo by: Gina Coleman/Weedmaps
Keep your environment at the right temperature and humidity
Growing your seedlings indoors with artificial light gives you more control over the process, making it easier to ensure your plants are getting enough light each day. If you’re growing with artificial lights (compact fluorescent lights that emit cooler, blue spectrum light are especially effective), aim to give your plants 18 hours on and six hours off each day.
You should also aim to keep humidity in the grow environment at a higher level, typically around 70 percent. That way, the plants can absorb moisture from the environment to develop stronger roots without getting weighed down by over-watering.
Choosing the right pot is an essential part of caring for your growing plant. You need a pot that’s going to give the root system space to grow, but not so much space that the roots won’t be able to absorb all the water in the soil. You should also make sure the pot has drainage holes to get rid of any excess water that could overwhelm the plant.
Before we jump into how to care for your cannabis seedling, let’s quickly cover what happens during this grow stage.