Jorge’s Cannabis Encyclopedia: Seed Germination


Cannabis seeds need only water, heat, and air to break dormancy and germinate; they do not need extra hormones, fertilizers, or additives. Seeds sprout without light in a range of temperatures. Strong, viable, properly nurtured seeds germinate in 2 to 7 days. At germination, the outside protective shell of the seed splits, and a tiny, white sprout (radicle) pops out. This sprout is the root, or taproot. Cotyledon, or seed, leaves emerge on a stem from within the shell as they push upward in search of light.

Break dormancy: Put newly harvested seeds in the refrigerator for a week or two to simulate winter. Remove and germinate. Seeds will germinate more uniformly because they all come out of dormancy at the same time.

Timeline for Germinating Most Seeds:
At 36 to 96 hours – Water is absorbed, root tip (radicle) pops through outer shell and is visible.
At 10 to 14 days – First roots and root hairs become visible.
At 21 to 30 days – At least half of seeds are rooted by day 21. Seeds not rooted by day 30 will probably grow slowly.

Once seeds are rooted, cell growth accelerates; stem, foliage, and roots develop quickly. Seedlings develop into full vegetative growth within 4 to 6 weeks of germination.

Seeds are Prompted to Germinate By:
air (oxygen)

Water: Soaking seeds in water allows moisture to penetrate the protective seed shell within minutes. Once inside, moisture continues to wick in to activate the dominant hormones. In a few days, hormones activate and send enough signals to pro- duce an initial root tip. The white radicle (rootlet) emerges to bring a new plant into the world. Once a seed is moist, it must receive a constant flow of moisture to transport nutrients, hormones, and water so that it can carry on life processes. Some seeds need lots of moisture to wash out the dormancy hormones in the seed coat, and if they do not get enough moisture, they do not germinate. Conversely, too much water deprives the seed of oxygen, reducing its quality or destroying it. If fragile germinated seeds are allowed to suffer moisture stress now, seedling growth will be stunted. Soaking most seeds in water for 12 to 24 hours is all they need to initiate germination. All the nourishment for a seed’s initial growth requirement is pulled from the fleshy cotyledons, or seed leaves. Water seedlings with low-EC (electrical conductivity) household tap water during the first week or two of life. Supple- mental nutrients are unnecessary and if applied in excess can disrupt internal seed chemistry. Some gardeners prefer to germinate seeds using distilled or purified water that contains virtually no dissolved solids.

Temperature: Overall, cannabis seeds germinate in temperatures from 70°F–90°F (21°C–32°C) and grow best at 78°F (26°C). Temperatures below 70°F (21°C) and above 90°F (32°C) impair germination. Low temperatures delay germination. High temperatures upset seed chemistry causing poor germination. Seeds germinate best under the native conditions and temperature ranges where they were grown.

Air & Oxygen: Sow seeds twice as deep as the width of the seed. For example, 0.125-inch (3 mm) seeds should be planted 0.25 inches (6 mm) deep. Adequate oxygen is un- available for seeds planted too deeply, and tender seedlings have insufficient stored energy to drive through deep layers of soil or crusty hard soil when sprouting.

Agricultural Astrology — Planting by the Moon 
Ancient Babylonians and Egyptians planted and harvested based on moon phases in relation to geographic location. The premise is that plants grow better when planted during the appropriate moon phase.

Moon phases cause ocean tides to rise and fall. They also affect the rise and fall of moisture in soil and fluids inside plants. The moon phase influence is said to be the same indoors, outdoors, and in greenhouse-grown cannabis.

Cannabis gardeners who plant by the moon report faster-sprouting seeds that grow into vigorous plants. However, scientific evidence is lacking in regard to cannabis and other plants’ relationship with agricultural astrology.

Seeds need oxygen from the air to germinate. Growing mediums that are too moist (soggy) will cut off oxygen supplies and the seeds will literally drown. Cannabis seeds germinate best when moisture is between 60 and 70 percent.

Excerpted rom the 596-page Cannabis Encyclopedia available HERE. Visit Jorge at


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