Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

Dip the brush in the pollen container and gently brush the pollen onto the pistils. Again, the breeder must have a steady hand to ensure pollen doesn’t become airborne during the process. This technique is perfect if the cultivator only needs to make a few seeds.

Collect male pollen and put a little on a small artist’s paint brush.

Brush a little pollen on female pistils to pollinate.

Cover pollinated female branch with a plastic bag to keep pollen from contaminating other females.

Seeded female.

Male flowers have fallen and stuck to this fertilized seeded female.

This green seed will be mature in a few weeks. ‘Rene’ courtesy Chimera Seeds.

A bathroom is a good place to isolate and breed plants. The male on the right is pollinating the females in the bath tub.

    After fertilization, most seeds will be fully ripe in about six weeks, although some may be viable earlier. As the seeds mature, they can split open the calyxes allowing the breeder to see the development of the seed within. Seeds are ripe when they are mostly dark brown or grey, well-mottled (tiger striped), and sitting loosely in the calyx. Green, yellow, or white seeds are almost always immature and not viable. (Sprinkle them on your salad or cereal.) To test the ripeness of the seed crop, you can sample-harvest a few seeds and try to press them between your thumb and index finger to test the firmness. If most of the seeds do not crush with a reasonable amount of pressure, it’s time to harvest. If seeds are left on the plant too long, some may fall out of the buds and germinate on the growth medium below. This is more common with sativa -dominant varieties. Indica varieties typically have more dense flowers, which hold the seeds more tightly. Breeders must remove seeds from indicas by crushing and sorting the seeds from the plant matter.
    Seeds are ready to plant immediately, but the initial germination rates may be low. Germination rates can be increased by drying seeds out post harvest, leaving them in a cool, dark, well-ventilated area for a few weeks, and then placing them in the refrigerator for one or two months before sprouting.
    Please keep in mind this is only a guideline intended for small-scale seed production. Any method where pollen comes into contact with a pistil will result in seeds. Often breeders and seedmakers will place multiple males, or multiple copies of the same male (clones from a father donor plant) in the seed production grow room with their chosen females when creating seeds. Placing these males in a well-ventilated room and allowing full release of pollen ensures the crop will be completely pollinated, and produces a vast amount of seeds per plant. Scale the process to suit the number of seeds you require.

The seed can be seen inside of the seed bract in the circle. The bud on the left contains a mass of seed bracts filled with seeds.
Seed Crop Care
    Typically, cannabis growers use a high-phosphorus, low-nitrogen diet during the flowering cycle. My personal philosophy is to give seed production plants a complete balanced diet throughout the seed gestation period, so all nutrients required for proper development of the seeds are available. Because most cannabis-specific flowering fertilizers are low on nitrogen, growers may wish to combine vegetative and flowering fertilizers to ensure a complete diet for their seed mothers. Flowering nutrient formulas often lack certain nutrients, and the gestation period is not the time to be starving plants of these needs. Provide a complete diet, and let the developing seeds have all they need.

Young seedlings require a complete balanced diet

Vegetative and flowering plants require the same fertilizer for good seed development
    I’ve found that complete, balanced, organic-based soil mixes produce the most healthy, viable seeds. Organic soils contain various bacterial populations that break down and digest soil amendments to make them usable by plants. ‘Sterile’ salt-fertilizer based soils do not support these bacterial populations, and while they do support plant growth, they lack the “alive” quality of an organic soil. Many growers agree that organically grown pot has more flavor and taste than pot grown on a synthetic salt diet. It could well be that these organic bacterial populations provide some benefit to plant health, and thus produce more mature, healthy, viable seeds.
Breeding Terms
    In order to have a discussion on breeding, there are some terms we must