There are several ways of producing feminized seeds. Some organic growers and many keen home growers still deliberately stress their cannabis plants, causing them to hermy. By collecting the pollen from these plants it is then possible to fertilize a female plant (or many) to create feminized seeds.
Most large scale and commercial operations use chemicals to produce feminized seeds. There are two main chemicals used. Gibberellic acid is generally considered the most effective but colloidal silver is cheaper and more readily available, and consequently more frequently used. There are many internet sites telling you how to make your own colloidal silver.
When the process is carried out, rather than hermy the whole plant, the chemical is applied at points on the plant’s branches, causing stress sites which will then produce male pollen sacs. As with shock methods, the pollen is then collected and used to fertilise other female plants.
Feminized seeds can be purchased from the Manchester Seed Bank, check out our selection here.