This article is part two of the Germination series. To learn about how to prepare your new seeds for planting, see our article Germination.
Planting After Germination
If you used a soil-less methods of germination (such as the one outlined in our Germination Guide, you will need to plant the seeds in soil or your hydroponic medium once the taproot is about 1 cm long. Always take great care – the little seedling is very fragile and can easily be damaged.
After germination, don’t touch the roots – or even the seed, if you can avoid it – and try to prevent the roots from being exposed to light for any length of time. Always place the seedling root-down into the hole in the soil or hydroponic medium.
If you plan to move your cannabis plants to a larger pot once they have grown a bit bigger, consider first planting your seedlings in a plastic cup. This way, when you transplant the young crop, you can simply cut the cup away around the soil, rather than stressing the plants by pulling them up.
Planting in Soil
Make a hole about twice as deep as the seed is long, so the seedling will sit no more than 1 or 2 cm below the surface. Plant the seedlings deeper than this, and the stem and first leaves may take too long to reach the surface, and not get the light they require.
Much like using the germination method of planting seeds into soil, make sure the hole is moist before placing the seedling. Water sparingly after placing the seed, before covering it gently with soil. Afterwards, allow the surface of the soil to dry out before watering, to prevent drowning the delicate seedling.
Miracle Gro is not recommended for cannabis plants. It contains a large amount of nitrogen that releases over time, which will be detrimental once the flowering stage begins. The mix is also a bit low on the other nutrients – potassium and phosphorous – which are essential to cannabis plant health.
Planting in a Hydroponic Medium
There are many different soil-less growing mediums available. Some come as prepared cubes, with a hole already in the center into which you can simply place the seedling after the germination stage. These mediums are also suitable for the new seeds, prior to germination.
Some of these cubes will break down, and can be used when planting in soil as well. Others, like rockwool (also called stone wool) will not break down, and must be well rinsed before using, to lower their high pH.
A mineral such as vermiculite can be sprinkled over in lieu of soil, once the seedlings have been placed in the hydroponic growing medium.
After germination, and once the seedlings have been planted, you can begin the vegetative stage lighting ratio immediately. 18 hours of bright light followed by 6 hours of complete darkness is considered ideal for vegetation.
If the seedlings will be moved outside once they have grown a bit, acclimatize them to their future home by placing them on a windowsill. Using the high-intensity bulbs intended for indoor growing when they will eventually be getting sunlight can cause problems down the road.
If you plan to keep the plants indoors, the lights should be placed about two feet above the soil, and continuously raised as the plants grow, to maintain this distance. The exception is fluorescent lights, which can be kept closer to the plant.
First Two Weeks after Germination
You should see the little head of your cannabis plant peeking above the growing medium within a few days of planting your seedlings, but don’t panic if it takes a bit longer than this. Certainly don’t try to find the seed and check on its growth, as this can stress or even kill your baby plant.
If you have planted your seedlings in soil, you shouldn’t need to start adding nutrients to the water until around the third week. If you are using a sterile hydroponic medium, you may want to begin adding nutrients around the second week.
When you see the first sprout of your cannabis plant, you might find yourself wondering if you planted the wrong thing. The initial pair of leaves – called the cotyledons – will be smooth-edged. But don’t worry, the next pair to develop will have the serrated edges we all identify with cannabis plants. Those first “real” leaves may only have a single leaflet, but the next set should have two or three, and this number will keep increasing.
- Cannabis seeds come in many different colours, but those with the greatest chance of completing germination will be dark brown. White or pale green seeds will sometimes not be viable, but try them all before disposing of any.
- Some growers believe seeds are only viable for germination if they are hard – if they cannot be crushed between the fingers. This is not necessarily true so, again, attempt germination with all the seeds. If the seed sprouts a root, it should grow a plant.
- Sometimes the tiny stem that protrudes from the growing medium, following germination and planting, will be white and may look like the root, but it’s probably just the early stalk. Don’t try to turn the seedling around in the medium – give it time to develop.
- Lower quality or cheap seeds are less likely to succeed in the germination stage. Only buy seeds from a reputable dealer, like Growers Choice Cannabis Seeds.