Direct Seed Germination

Marijuana Horticulture

by Jorge Cervantes

One of the problems with rockwool an be that the seeds heave out before germinating. this is why it is best to germinate seeds before putting them into rockwool substrate.

Once seeds have sprouted and the white sprout is visible, carefully pick up the fragile sprouts (wit tweezers) and plant them in a pre-drilled hole in the rockwool with the white tip pointing down. Take care not to expose the tender rootlet to prolonged intense air or light. Cover the germinated seed with one quarter or half inch of moist rockwool. Keep the rockwol evenly moist. Once the taproot sprouts, small fuzzy feeder rots will grow in 12-14 days.

Water penetrates the outer protective shell, continues to wick in, and activates dormant hormones that induce germination. Once a seed receives moisture, there must be a constant stream of moisture to transport nutrients, hormones, and water to carry on life processes. Letting germinated seed suffer moisture stress now will stunt or stop seedling growth. The black tip of the root tells me this is what has happened.

Soggy growing mediums cut oxygen supplies and cause seeds to drown. Planting seeds too deeply causes poor germination. Seedlings do not have enough stored energy to force through too much soil before sprouting. Plant seeds twice as deep as the width of the seed.

Seeds do not need any extra hormones to germinate. Average household water contains enough dissolved solids to feed seeds through their first few weeks of growth. Supplemental nutrients will disrupt internal chemistry. Some growers prefer to sue distilled water which contains virtually no dissolved solids to germinate seeds.

Sow (direct seed) or move the sprout into a shallow planter, small seed pot, peat pellet, or rooting cube. Keep the plating medium evenly moist. Use a spoon to contain the root ball when transplanting from a shallow planter. Peat pellets or root cubes may be transplanted in two to three weeks or when the rots show through the sides. Feed with t dilute, quarter-strength solution

Construct a moisture tent over the seedling container to help retain even grow-medium moisture. To build, place a baggie or piece of cellophane over the seeded soil. The cover will keep the humidity and temperature elevated. Seeds usually need only one initial watering when under a humidity tent. Remove the cover as soon as the first sprout appears above ground. Leaving the tent on after seeds sprout through soil will lead to damping-off and other problems.

Place planted seeds under an HID lamp to add dry heat while germinating. The heat dries soil, which requires more frequent watering. Place a heat pad or soil heating cables below growing medium to expedite germination. Marijuana seeds germinate and sprout quickest when the soil temperature is between 78-80F and the air temperature is 72-74F. but stems will stretch between internodes if temperatures exceed 85F for long.

Over-watering and under-watering are the biggest obstacles most growers face when germinating seeds and growing seedlings. Keep the soil uniformly moist, not waterlogged. Do not let the growing medium surface dry for long. Keep it evenly moist. Setting rot cubes or planting flats up on a grate allows god drainage. A shallow flat or planter with a heat pad underneath may require daily watering, while a deep, one gallon 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. When the surface is dry (0.25 inch deep) it is time to water. Remember, there are few roots to absorb the water early in life, and they are very delicate.