We finally got our much needed rain and purslane is here with a vengeance. Once again we are pulling and hoeing and spraying purslane to keep it from totally invading our gardens. It is very persistent and seems to be back within 24 hours.
Common purslane is a weedy summer annual that is abundant throughout the world and is considered to be the eighth most common and ninth most unwanted plant. It invades gardens, vegetable crop production areas, lawns, orchards, and many other areas. It loves warm, moist conditions. Purslane is actually edible and is supposed to be a very good salad plant. It has been cultivated in Europe since the Middle Ages. In some areas of the U.S., purslane is a minor crop because of its use in ethnic cooking.
Common purslane often forms a dense mat. The reddish to flesh-colored stems branch from the center like spokes in a wheel up to about 12 inches long. The leaves are generally opposite, but can occur alternately along the stem. The flowers are yellow, about ⅜ inch with five petals and generally open only when it's sunny. Purslane is a very heavy seeder. In late summer, if you turn over the flat mats of mature purslane, you will find thousands of seeds on the soil surface. Common purslane germinates when the soil temperature reaches about 60 degrees F. It germinates very near to or at the soil surface in large numbers after irrigation or rain. The fleshy stems can stay moist for several days after cultivation and hoeing and root again to form new plants, especially after a rain.
Because of purslane’s ability to produce large numbers of seeds, it can rapidly multiply. A few scattered plants in the first year can become an almost solid carpet of purslane the next year. Common purslane forms dense mats, uses available moisture and nutrients and screens out light to the soil surface, preventing other seedlings from growing.
Prevention is the best form of control for common purslane since once it gets established, it is very difficult to control and eliminate. Check often, especially after a rain, for purslane seedlings and hoe or pull while they are still small. It's very important to remove purslane debris from the area and make sure they get no sunlight.
If your mulch screens out ALL light, it can be used to control Common purslane. Mulch should be at least three inches thick. You can also use synthetic mulches. If they screen out light and give a barrier to seedling development, they work well.
Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange County.