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cannabis seed starting temperature

Timescales can vary, as it all depends on how ideal your germination environment is (see the golden rules above). Even the worst grower could make a seed germinate, but it may take a few weeks and, of course, increases the risk of a weaker plant.

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.

• 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

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.

The ideal is to maintain the germination medium at about 26-28ºC and at 70% relative humidity. Lower values ​​will result in a slower and less successful germination, while higher values ​​can bring fungal or rot problems.

* You will also need a measuring cup and a stirrer (not included in the Seedkit).

So, you should plant the seed with the tip down and the crown uppermost and facing you. Once the seed germinates the crown will serve as a hinge, so that the seed will open at the tip and let out the root. In case of placing the seed incorrectly, the tap root will grow upward and the seedling downwards, which should be avoided at all costs because it is likely that the seedling will not be born.

Direct germination in soil

A heated greenhouse is perfect for germinating seeds

Another common mistake, in this case when germinating in kitchen paper or similar, is to let the seed germinate until the cotyledons appear. If we do this, then the subsequent transplant is very difficult, and it is very likely that we’ll damage the root in the attempt. Additionally, the longer the root is exposed to air and light, the more damage will result, so it is preferable to transplant it before this occurs.

Although the germination of cannabis seeds is a relatively quick and easy process, it is crucial to take into account a series of important factors in order to obtain as high a germination rate as possible. In addition, it’s in our interest that the seeds germinate as quickly as possible, and especially if we want to avoid problems like fungal infection or a low germination rate.

This is a common mistake that usually results in non-germination, especially if the substrate hasn’t been previously watered before sowing the seed but is watered afterwards. By planting the seed directly in the substrate, we run the risk of it being buried too deep, made worse when we irrigate the growing medium post-sowing.