July 18, 2015

1 - Sedum groundcover may be used to create a sedum lawn, but be sure the plants covering the ground are actually sedum.

Yard and Garden July 18, 2015

Q.

Is this plant a sedum (photograph sent)? It is taking over my yard and looks like it could be a good groundcover plant. I have heard of sedum being used as a lawn substitute. However, this plant does not do well when walked on. A white sap comes out when the stems are broken. Is sedum a good choice to replace my lawn?

A.

The plant taking over your lawn is called spotted spurge, Euphorbia maculata. It is usually considered an undesirable weed. That milky sap (technically latex) you described is a mild skin irritant and can cause a skin rash in some people. This latex is poisonous if ingested. The latex of some spurge plants has been determined to contain compounds that are carcinogenic. If you get the latex on your skin, wash it off. Once it has dried, it will not wash off with water, but can be removed with skin lotion. This is probably not a plant you want to grow as a lawn.

Sedum plants on the other hand, are more desirable plants that can indeed be used as a very low water requiring lawn replacement. They are also known as stone crop plants and are usually succulent plants that store water in their tissues to survive dry periods. They have a clear sap when the stems and leaves are broken or crushed. They will not tolerate food traffic, so stepping stones may be needed to provide walkways across the sedum lawn area and to allow access to allow removal of weeds that will manage to grow up through the sedum lawn. They may also be grown in rock gardens and even in cracks in rock walls.

A sedum lawn may be maintained by natural precipitation supplemented by runoff from your roof during rains. Supplemental irrigation should be used very sparingly since the sedum plants may be subject to diseases if they are kept too moist. For this reason they will need a soil that does not stay wet long after rains.

Sedum plants come in various sizes and have different appearances. Many sedum plants are low growing succulent (juicy) plants. They may have broad flat leaves, or round, tubular leaves. They are all thick because they are used for water storage for the plant. Some have leaves with yellowish coloration, some are green with silver edges, some are green, and some are frosted looking. Combinations of these leaf characteristics may be useful in landscapes when the plants are grouped artistically.

Some of the taller sedums, such as Sedum spectabile, have been reclassified and are now in the genus Hylotelephium. These renamed sedums and others may have attractive flowers to enhance the pseudo lawn. Flower colors range from white, to yellow, to pink, to red. In the fall and winter some sedum plants can develop red and purple tinted leaves.

Sedum lawns will not tolerate mowing, but because most are low growing, they will not need mowing. The taller varieties should be planted in locations where they contribute to the landscape, but should also not be mowed. The taller varieties can be cut to the ground after flowering.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

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