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how to germinate marijuana

Over and under-watering are the biggest obstacles most gardeners face when germinating seeds and growing seedlings. Keep the soil uniformly moist but not waterlogged. Do not let the growing medium’s surface dry for long. Setting root cubes or planting flats on a grate allows good drainage.

1) Soak seeds overnight in a glass of plain water. They may float on the surface at first but should sink to the bottom in a few minutes. Make sure seeds get good and wet so that water penetrates the outer shell and growth is activated. Do not let seeds soak for more than 24 hours, or they might get too wet, suffer oxygen deprivation and subsequently rot.

Jorge Cervantes shares his process for germinating cannabis seeds into healthy sprouts.

Other Tips for Germinating Cannabis Seeds

3) Shake matchbox for 10 to 15 seconds to scarify the seeds.

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.

Some seeds have a very hard outer shell (testa) and are difficult to germinate. Such testy cases can be softened or scarified to allow water to penetrate. To scarify, line a matchbox with a piece of fine-grain sandpaper or emery board. Put the seeds in the matchbox and shake for 10 to 15 seconds. Remove the seeds and make sure they have been scuffed a bit. Just a little scuffing will allow water to enter and set germination in motion.

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.

Even if your seed sprouts fast and grows vigorously, it still has roughly a 50/50 chance of being female and producing buds, instead of turning out to be a male.

However, a type of cannabis called Cannabis ruderalis, which developed in extreme northern conditions without much sunlight, will begin flowering once the plant reaches a certain age—they automatically start flowering regardless of the amount of light they receive, hence the name “autoflower.”

Also, buying from a reputable breeder or seed bank will give you a sense of what a particular strain will look and smell like, how it will grow, and how much it will yield at harvest.

Time to germinate

For a seed to be viable, it must be mature enough to have a completely formed genetic blueprint, and it must be strong enough to germinate and pop through its hard casing and sprout its crucial taproot.

However, potency in autoflowering varieties has increased significantly since their initial introduction, with some breeders crossbreeding the low-THC ruderalis with other more potent varieties.

As we’ve mentioned, cannabis is a dioecious plant, meaning male and female reproductive organs appear on different plants.

Through cloning, you can create a new harvest with exact replicas of your favorite plant. Because genetics are identical, a clone will give you a plant with the same characteristics as the mother, such as flavor, cannabinoid profile, yield, grow time, etc. So if you come across a specific strain or phenotype you really like, you might want to clone it to reproduce more buds that have the same effects and characteristics.

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.

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.

The soil pots will need small holes (roughly 10–15mm deep) for the newly germinated seeds to be placed into. Once the seeds are secure, you will want to place a fluorescent light 13–15cm (5–6 inches) away to encourage growth. Finally, don’t risk overwatering your seeds at this early stage. Use a plant mister to make sure they stay damp but not soaking wet.

PLANTING DIRECTLY INTO SOIL

• The ideal temperature is between 22° and 25°C (71–77°F)
• Your growing environment should be damp/moist, but never wet
• Relative humidity range should be between 70% and 90%
• Seeds favour fluorescent lighting (Cool White code 33)
• Minimise the amount of seed handling you do
• In hydroponic/rockwool plugs, the ideal PH value is 5.8–6.2

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).

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.

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.