Rub the indigo flowers until the brown or black seeds are exposed. Viability is very high so they should all germinate. I plant mine in the greenhouse around the first of May so the seedlings are ready on June 1 or after the last frost in your area. If you don’t have a greenhouse just start in tray in the house and keep in sun after germination.
Plant in garden about a foot apart. They are frost sensitive but very little else bothers them. When they begin to flower, they are ready to use.
Japanese Indigo is a buckwheat so it enriches your soil and requires very little nutrient in order to produce profuse plants. Because the flowers don’t often open until after the first frost in the fall, cut the ones that have buds or flowers and put in bucket of water. Bring in the house away from frost. The stems will root and the plant will continue to produce flowers which self pollinate. Around December or January, you will have seeds. Just feel the dried flowers to see if the seeds are firm.
Rub the dried flowers and seeds will drop out. Save these to plant next year.
Watch for small aphids that seem to hatch out in November. Because of this problem, keep the indigo bucket away from other plants and out of the greenhouse at this stage, however, they do seem species specific.
If you would like some seeds to try, contact Cynthia.
Ten plants should dye about a pound of wool.