For most people growing herbs their goal is to keep the plant from flowering as long as possible. The last thing a home gardener wants is for their supply of tasty pot herbs to bolt, because the majority of them will not have the desired flavor once the plant starts building blooms. Some herbs can taste terrible once the growth stage shifts like this, but the will give you a great supply of seed to grow new crops from.
Like any fruit or vegetable, getting the desired result from collected seed means knowing when to pick it. Basil is no different. Seed harvested before it is mature will not work out real well. It must have reached it’s fully reproductive stage still attached to the plant, or your germination rate may very well be zero.
It could take weeks between the flower petals dropping off and the seed being ready to collect. Never pick seed pods that contain moisture or green seeds. Let nature take it’s course. Harvest hard, dry seeds only – the pod may look dried but the seeds inside might not be ready yet. Always peek before you disconnect them from the plant.
Basil seeds are carried in the bract beneath each bloom on the stem. Since this plant flowers in a ‘stack’ at the tip of the stems, you could easily get dozens of viable seeds from a single stem allowed to set flowers. There are those who say that basil is one herb that the leaf flavor is still pleasant after the plant bolts, but others claim it no longer tastes good. But if you simply let one stem bloom and keep the others pinched back, you should still have a supply of fresh basil for the kitchen while you’re also producing seed. You won’t be able to hold off the blooming forever, but you can delay the inevitable.
Each flower will give you 4-5 seeds arranged in a circle around the center of the pod where the plant stem attaches. When they’re ready to collect, they will be hard and black. Be sure to open the dried pods over an envelope or cupped piece of paper. They are tiny, round seeds which will bounce and roll when they hit the nearest surface. When basil seeds are ripe, they will easily detach from their holding place in the pod – so don’t shake the plant or stems around a lot, or you could lose a portion of your seed crop before you try to harvest it.
Here’s a nice video that shows you what ripe basil seed looks like and how to harvest it.
Easy peasy. Good seed that will germinate readily if you start it properly. You’ll never have to buy a new plant at the store, or pay for basil seed again.
Be sure to store your basil seed in an airtight container, and in a cool, dark place. Moisture and exposure to sunlight can ruin seed, and decrease your germination rate considerably. A small freezer box works great. Just wrap your seeds up in a piece of paper held together with a paper clip, and they will keep for several years.