Producing Female Seeds (by shaky).
If it were possible to know which seeds are female and which are male, marijuana growing would be even simpler than it is. There is not practical way to discern the gender of a seed - but there is a simpler procedure for producing seeds that will all grow into female plants.
To produce female seeds, the plants are fertilised with pollen with male flowers that appear on a basically female plant. Such flowers appear on intersexes, reversed females, and hermaphrodites. Female plants have an XX complement of sex chromosomes; therefore, the pollen from the male flowers that form on female plants can only carry an X chromosome. All seeds produced from flowers fertilised with this "female" pollen will thus have an XX pair of sex chromosomes, which is the female genotype.
Although the male Cannabis plant can produce female flowers, it cannot produce seed; so there is no chance of mistakenly producing seed on a male plant. It is possible to use pollen from an intersexual plant that is basically male (XY); the resulting crop of seeds will have the normal 1:1 ratio of males to females. For this reason, choose a plant that is distinctly female as a pollen source. A female plant with a few random male-flower clusters, or a female plant that has reversed sex are both good pollen sources. The seed bearer can be any female, female intersex, or reversed-female plant.
In most crops, careful inspection of all the females usually reveals a few male flowers. And often, when females are left flowering for an extended period of time, some male flowers will develop. If no male flowers form, you can help to induce male flowers on female plants by severe pruning. One such procedure is to take the bulk of the harvest, but to leave behind some green leaves to maintain growth. Most of the plants will continue to form female flowers, but male flowers are also likely to form. At times, the plants may not grow particularly well, and may in fact form distorted and twisted leaves, but they will produce viable seeds as long as some stigmas were white when pollinated. (Remember, it only takes a few fertile buds to produce hundreds of seeds.) Pollinate the female flowers by hand as soon as pollen becomes available.
Double Harvests added by j.k.t
Most marijuana plants take at least five months to reach maturity. Once the plant has reached maturity, it is forming its most potent marijuana, and should not be cut down completely. You can often induce the females to flower a second (and sometimes a third) time, especially if the plants are indoors or if the weather is expected to stay mild for several more weeks.
To encourage a second bloom, first take the bulk of the harvest: all but the smallest buds, and most of the leaf. Some green leaves should be left on the plant to maintain the plant's growth. After harvesting, give the plants a thorough watering, and water with a soluble, complete fertiliser that provides a good supply of both N and P. This will encourage new growth and continued flowering.
Indoors, the best procedure is to treat the plants like a hedge. Cut all the plants back to equal heights, about two to three feet tall. Remove most of the grass, but again leave a few green leaves on the plant. Don't remove lower branches even if they are leafless, since these will sprout again. Lower the light system to the tops of the plants, and maintain the daily cycle at about 12 hours. The second crop of buds will be ready for harvest in four to eight weeks. With this system, the plants appear like dense hedges of buds. If the second crop of buds forms quickly, you should try for a third crop. Continue to fertilise the plants regularly, and watch for signs of magnesium deficiencies, which often show up when the plants have been growing for an extended time.
Double and triple harvests are one of the benefits of indoor growing. Although plants are relatively small indoors, the original harvest of buds can be triples in the next four months.
revegging plants after harvesting.
After the buds are harvested, you may realize just how much you want to perpetuate a plant you neglected to take cuttings from. Cut the main stalk down to the point where below several growth tips or buds are remaining. Return the plant to a vegetative fertilizer and photoperiod. Over the next several weeks, the plant will elongate and devlop new upward growth. It is very important not to overwater the plant after it has been cut back. The reduced above ground plant structure is still being fed by the entire existing root system, which can cause an excessive amount of water uptake and the resultant stress associated. The use of products containing ammonium form nitrogen, such as chicken manure or Genesis Formula Grow 2 will encourage rapid growth and stem elongation. Trace element supplemenation, co2 and 24 hour lighting are helpful.
LUDACRIS.