Unfortunately, regulation and implementation in respect of cannabis seeds often differ from country to country. For this reason we advise you as a matter of urgency to make inquiries about the regulations to which you are subject. Read the complete disclaimer here.
This article explains how to correctly germinate your cannabis seeds, covering everything from optimum temperatures, to potting your seedlings and transferring them outdoors (or inside under lights).
Step 1. The setup – How to germinate cannabis seeds
Lastly, cover everything with the second plate, upside down, to form a ‘clam-shell’ shape – this will create the dark, moist environment necessary for germination.
Place the plates somewhere warm (21ºC) and away from direct light.
When the first few millimetres of root have emerged from a germinated seed, each one should then be carefully transferred to a small container of growing medium (soil, coco-fibre or rockwool).
Three fundamental principles will trigger that first small taproot to appear: warmth, moisture, and darkness. With the promise of moisture, a single root will take shape before slowly developing into the cannabis plant we know and love. In the right conditions, seeds will begin to develop within 12–36 hours of moisture being introduced to them.
Start by filling pots with a premium-quality soil that has been soaked in water. Many growers also choose to lace the water with a root stimulator. Make a hole roughly 10–15mm deep. This will be your seed’s new home. Remove the seeds from their packet and place them into the pre-dug holes. Loosely cover the seeds, but be careful not to compress the soil above the seed too much. The root will struggle to penetrate solid soil, slowing plant growth. Lightly spray the top of where you placed the seed so that your growing medium stays moist.
WHAT IS AN EXPECTED GERMINATION TIME?
The dome of the plastic container will create your seeds’ own mini tropical climate. If you then place all the components in a temperature-controlled cupboard, you will have created a self-perpetuating supply of moisture—no need to touch the seeds again until they are ready to be transferred to your final growing medium as a young seedling. Using the stone wool block method, your seeds should germinate in one to two days.
Small, fragile, and in desperate need of a helping hand, there are several ways you can germinate your cannabis seeds. All methods have varying degrees of success, with both advantages and disadvantages. It is important to note that even with advanced growing expertise and top-of-the-line equipment, you may still end up with a few failed seeds. This is a natural part of dealing with a living organism. At Royal Queen seeds, we only sell feminized cannabis seeds, so there is no need to worry about removing male plants.
Maintaining the ideal temperature (between 22–25°C/71–77°F) and moisture for germination is tricky. Leaving seeds out in the open environment or on a windowsill is far from ideal; a DIY climate-controlled cupboard would do a much better service. A warming mat is perfect for maintaining a constant temperature, but it doesn’t tackle the issue of moisture.
Unfortunately, by the time your seedlings show the first signs of damping off (a limp and discoloured stem), there’s nothing you can do to save them. We just recommend removing the affected seedlings from your grow room or propagator ASAP to avoid spreading the fungi.
Carefully place your cannabis seeds between a few moist pieces of paper towel, and place it all in a plastic container with a lid. Keep the container in a warm, dark place (temperatures between 20–25°C are ideal). Leave a slight crack in the lid to allow for some fresh air exchange.
Remember, rapid growth and vibrant green foliage are telltale signs of healthy seedlings.
HOW TO WATER YOUR SEEDLINGS
Cannabis seedlings like daytime temperatures of 20–25°C and nighttime temperatures that are roughly 4–5°C cooler. High temperatures will stress your seedlings and stunt their growth, which, at such an early stage, can prove fatal. Dry leaves with curled up edges are a telltale sign of heat stress. With time, your seedlings might also develop other symptoms, including pale foliage and red or purple stems. Heat stress can also cause weak, wilting leaves with downward folding tips.
Cannabis seedlings are super fragile and can easily “burn” in nutrient-rich soil. In general, we don’t recommend feeding during the seedling phase. Instead, keep your seedlings chilling in their Easy Start pots until they’re ready to be transplanted and start vegging.
Luckily, unlike some of the other seedling issues we’ve mentioned in this post, it is possible to remedy nutrient burn. Simply lay off the nutrients for at least one week and water your plants with plain, pH-balanced water. Once your plant starts to grow more healthy, green foliage, slowly dial the fertiliser back in.