I have 5 groupings of basil plants, each containing between 5-7 unique plants. I would like to produce enough seeds (say 100) to replant the same total amount of basil next season. I have throughout the season been pinching out flowers to delay the plants.
How many groupings of plants should I stop pinching out in order to produce the desired amount of seed?
If you want to be able to collect seeds from year-to-year indefinitely without a decline in the health (genetics) of your basil population, you should collect seed from at least 20 plants.
You will also want to be careful to select seed from only the "best"1 plants. If you collect seed from weaker plants then you are not removing weak genes from the pool and the quality of the plants you get from your collected seed will suffer after a couple of generations.
1 For whatever value(s) of "best" is important to you: flavor, vigor, disease resistance, etc.
Okay, if they're all the same variety, assuming normal pollination occurs, you should get a good number of viable seeds from just one plant, so if you want to continue cropping, pinch out the flowers from half your crop as you have been doing, and let the other half go to seed. Although most likely, you will only need to let about 1-3 plants seed, but just to be on the safe side... How many seeds to an individual seed pod or plant is hard to predict, it's not an exact science.
