Two or three weeks after germination, your young seedlings should be ready for their new home. At this point you have two options; transplanting them into soil pots, or taking on the challenge of hydroponics. You’ll know when the seedlings are ready to be moved because the root system should start to poke out of the bottom of the wool blocks. As long as the roots haven’t begun to engulf the bottom half of the wool block, they will seek out water and nutrients in their new surroundings and continue to grow downwards.
Often overlooked, it is all too easy to assume that the vegetative and flowering stages of cannabis growth are the most critical parts of the plant’s life cycle. However, with the chance of failure high unless you know what you’re doing, poor planning when it comes to germination can make or break your next grow. Giving your cannabis seeds the best possible start on their journey to bulging buds is a surefire way to encourage a healthy and robust plant.
Regardless of where you get your seeds from, it is best to give them a slight (and delicate) inspection before planting. Most of the time, all seeds will germinate; however, poor-quality seeds will produce a weaker plant. Unfortunately, that is something you will not find out until well into the vegetative and flowering stages.
USING STONE WOOL BLOCKS
After 3–5 days, the seeds will start to open, and you should see tiny white tips appear. Once these roots reach 2–3mm in length, use extreme care to transfer them from the water to pre-prepared soil pots.
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.
To avoid disappointment, seeds that have a darker colouration stand a better chance of germinating, while pale green or white seeds are likely to fail. Even if dark seeds look slightly damaged, they should be planted anyway. There is a good chance they will still germinate, even if the outer shell is somewhat crushed.
Arguably one of the least effective methods, but it is still viable. Incredibly simple to facilitate, beginner growers may opt to germinate their seeds in a glass of water. Half-fill a glass or bowl with water that is approximately 22°C (71°F).
A shallow flat or planter with a heat pad underneath may require daily watering, while a deep, 1-gallon (3.8 liter) pot will need watering every three days or more. A properly watered flat of rockwool cubes needs water every three to five days when sprouting seeds.
Other Tips for Germinating Cannabis Seeds
When the growing medium’s surface is dry (0.25 inches [1 cm] deep), it is time to water. Remember, there are few roots to absorb the water early in life and they are very delicate.
4) Place the seeds in a warm location (70°F–80°F; 21°C–27°C), making sure they are in darkness. Some gardeners go so far as to set the plate in a vertical position (so taproot grows downward). The seeds can also be set on a grate for drainage and air circulation.
2) Remove seeds from the water. Pour water out onto two paper (or cloth) towels on a dinner plate. Fold the towels over the seeds to cover them.
The gardening season is booming in North America, and it’s high time to start some tiny seeds that can grow into potent plants, says Jorge Cervantes, veteran marijuana cultivator and author of “The Cannabis Encyclopedia”.