About Ground Plum: This nitrogen fixing legume grows well in almost any type of dry ground, and can be found sprawling over gravelly slopes or clay banks where few other plants would dare to establish themselves. Its unusual plum-like fruits were sometimes called the “food of buffalo” by Native American tribes, though the raw or boiled fruits were also a favorite food of both Native Americans and early settlers. English naturalist Thomas Nuttall first documented this species in 1810, on an expedition to North Dakota’s Mandan settlements. The Latin name “crassicarpus” means “thick-fruited.”
Ground Plum Germination: Before planting, scarify by pouring hot water over the seed and soaking it for 24 hours. For fall planting, direct sow the seed 1/2" deep; it will remain dormant until spring. Scarified seed can also be direct sown in early spring, but this plant does not transplant well and should not be started indoors. Germination may be slow. This plant adapts to many kinds of soil including sand, clay, or gravel, but prefers well drained soil and full sun; it cannot tolerate shade.
Growing Ground Plum Seeds: This plant grows rather slowly. Young plants may need occasional watering, but mature plants can tolerate drought conditions. Its low branches will sprawl along the ground. As well as being a good choice for rock gardens, this plant does well in heat and humidity and attracts butterflies and bees.
Harvesting Ground Plum: Though the young fruits are edible, Ground Plum strongly resembles various poisonous native plants, and its fruit should not be eaten without positive identification. The 1” unripe seed pods look like small plums, and can be eaten raw or cooked.
Saving Ground Plum Seeds: In midsummer, the 1” fruits will form, looking something like a purple and green plum. The seeds will be mature when the dry fruit eventually develops a thick, wrinkled tan skin and the seeds rattle inside. Remove the pods and open them to harvest the seed.
Detailed Ground Plum Info: Origin: US Native Other Common Names: Groundplum Milkvetch, Buffalo Bean, Buffalo Plum Duration: Perennial Bloom Time: Early Summer Height: 12-15 inches Spacing: 12-15 inches Light: Full Sun Soil Moisture: Medium to Dry USDA Zone: 3a-9b Seeds Per Oz: 5,500 Produces a low growing plant with foliage of many 2-4” compound leaflets, and clusters of tubular lavender blossoms.