Making Seeds Step by Step

Marijuana Horticulture

by Jorge Cervantes

Step 1

Choose breeding parents. Selecting female plants for breeding is a much easier task than selecting males, because female plants readily demonstrate all the traits that are essentially important to a grower, or smoker. The breeder may want to place an emphasis on selecting for potency, flavor, yield, smell, resistance to pests, color, growth stature, etc. Cannabis for consumption is a group of pistillate flowers; a bud is a collection of pistillate flowers; a cola is a group of buds. All a grower has to do is watch these flowers develop over the life cycle, harvest, smoke a bud sample from each plant, and determine the positive characteristics of each plant, for its growth as well as its smoking characteristics. Post harvest evaluation allows additional inspection of aromas and flavors, since these can change as the flower dries and cures.

Choosing male plants with desirable characteristics is not so easy. Males obviously don’t produce female flowers; thus, judging resin content, floral structure, smells, etc., is more of an inferential task – males just don’t demonstrate these characters. Some breeders feel a good method for choosing a potential male is to rub the stem with your finger. The idea is if it exudes a pungent, resinous odor, it may be a good plant. This is really only a crude measure of the odor of the candidate. Although it can be a useful technique, it certainly should not be the major selection criteria.

The best method for determining a potential male’s contribution as a breeding parent is the progeny test. Progeny testing is achieved by taking pollen from a potential breeding male and using it to make seeds with the chosen female(s). The resulting seed population is grown out and examined to determine the effect of the male on the progeny. Progeny tests are without doubt the most reliable method for determining the genetic value of the chosen male as a contributor to the next generation – a concept known as combining ability. One drawback of the progeny test is that it takes time to grow and evaluate the progeny, and the potential male plants must be kept alive if they are to be used again. Sometimes breeders choose to not keep these males alive, only keeping the progeny lots that correspond to the better male plants and destroying the rest. Only the best performing males are allowed to make a genetic contribution to the next generation.

Step 2

Collecting pollen. One branch of male flowers will supply all the pollen necessary fr small scale breeders to produce ample seed for their use. Strip away other branches to guard against accidental random pollination, and to avoid premature pollination, isolate the male as soon as anthers show. Be considerate of the fact that airborne pollen can travel miles. If you brush up against a plant in dehiscence, pollen will become airborne and travel throughout the area.

Just prior to the anther’s opening, place a clean paper or plastic bag over the branch. Secure the bag at the bottom with a piece of string or a wire tie to prevent pollen from escaping. Keep the bag over the branch for several days to collect pollen. When enough pollen seems to have been collected, tap the branch and shake remaining pollen off into the bag. Carefully remove spent branch and bag so the pollen does not escape.

Step 3

Store and protect pollen (optional). Pollen does not have a long shelf life under natural conditions; it is easily destroyed by high temperatures and moisture. Pollen can, however, be stored in the freezer for several months, if needed. This is accomplished by carefully removing the pollen from the collection bag and subsequently passing it through a screen. This removes any leaf matter from the anthers that may have fallen into the bag and contaminated the pollen, causing it to spoil. Wax paper is placed under the screen, and used to catch the pollen. The pollen can then be collected with a sterile scraper, placed in a small coin envelope or sterile test tube, and placed in the freezer. Cleanliness counts! Pollen should not be repeatedly frozen and thawed, which will decrease its viability.

Step 4

Pollination occurs when pollen comes into contact with the pistil. Depending on variety, fresh pistils are ready to pollinate from two to twelve weeks after flowering is induced. The more pistils on the bud at the time of pollination, the more seed will be produced. Fertile pistils appear turgid and most often are white or off-white in color. Pistils that are withered, rust or brown colored are past the point where successful pollination can occur.

To pollinate, cover the female branch with the pollen filled bag, and briefly shake the bag to ensure the pollen comes into contact with as many pistils as possible. Leave the bag for two days and nights t ensure thorough pollination. Be careful not to scatter pollen when removing the bag, as viable pollen can still become airborne and pollinate nearby plants. If other plants are in the garden and are not intended for pollination, the grower may move target plants from the main grow area into a separate, smaller space for pollination. After a couple of days in the pollen chamber with the males, the female plants are thoroughly sprayed with water to destroy any remaining pollen, before they are moved back into the main grow area where these seeds will mature over the coming weeks. This practice minimizes the possibility of pollen fertilizing the rest of the crop, keeping it seedless as the cultivator requires. To reduce or eliminate pollen contamination of future seed crops, make sure to clean pollination chamber between each pollen release.

An alternate approach is to use a small paint brush to “paint” pollen onto the pistils. 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.

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 calyzes allowing the breeder t 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 r 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 fr 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 f seeds per plant. Scale the process to suit the number of seeds you require.