Shepherd's needles prefers moist sites, but does well without irrigation through all but the most extreme droughts. Shepherd's needles is a fast spreading weed. They may be spread by wind or water, but are most often dispersed by people or animals who get the little seeds caught in their clothing or fur. It is seldom necessary to intentionally propagate shepherd's needles. Seedlings are usually abundant wherever plants have grown.
Plants are easy to transplant.
Usage Shepherd's needles is sometimes planted in butterfly gardens or wildflower meadows, but is usually regarded as a weed. In South Africa, Zulus and Indians eat the fresh or dried leaves. They are boiled in a little water and eaten alone or with cornmeal when more palatable and nutritious foods are scarce. Give shepherd's needles some space off along the far side of the yard where you can see the butterflies without getting the needles in your clothes and you won't have to pull zillions of seedlings out of the vegetable garden. If you don't want them by the dozens next year, you have to be diligent about pulling the plants up before they go to seed.