What is Portulaca?

Portulaca is a genus of flowering plants which thrive in hot, dry conditions like those found in its native South America. People who live in drought-stricken areas often use portulaca to add color and greenery to their gardens without the need for water, and this plant also grows well in containers. Many garden stores carry portulaca seedlings in the spring, and the plant can also be grown from seed, as long as the seeds are sown after the last chance of frost has passed.

You may also hear this plant referred to as purslane or moss rose. It is an annual, so it will die out when cooler weather arrives, but it can look good from the late spring all the way through the early fall, as long as it gets at least six hours of direct sunlight a day. Portulaca actually enjoys poor, sandy soil and minimal watering, so it's a great plant for areas of the garden where other plants wilt, such as flowerbeds in a relentlessly sunny area.

The plants in this genus all look slightly different, but as a general rule, they are creeping groundcovers with fleshy, spoon-shaped leaves and brightly colored flowers. In most cultivars, the flowers only bloom in sunlight, closing up at night or in overcast weather. The flower colors can vary, but white, pink, and yellow are all common, and some portulaca cultivars are bred specifically to have especially showy flowers.

Portulaca grows rapidly in the right conditions, and rarely climbs above more than four inches (10 centimeters) in height, typically forming a matted growth which hugs the ground. To keep moss roses tidy, it is a good idea to periodically dead-head them to remove dead flowers, and to trim away any foliage which browns or dies. Portulaca is hardy enough to be planted between paving stones and in other highly-trafficked areas, although it will usually be thinner in the areas where people walk.

Purslane is hardy in USDA Zones seven through 11, and in especially warm climates, it may make it through the winter and grow again in the following year. This plant also readily reseeds itself, although it does not usually breed true, so the new plants may not look the same as the original plants. Generally, portulaca does not reseed itself enough to become a serious pest, although it is regarded as a weed in some areas.