July 5, 2014

1 - New Mexico locust may grow in some high elevation New Mexico landscapes, but its thicket-forming habit may be undesirable.

Yard and Garden July 5, 2014


I am trying to identify a tree growing near my house outside of Santa Fe. Neighbors think it is a New Mexico locust, but all descriptions say that is a flowering tree, and mine does not flower. It does send up new sprouts all over the yard, however. Because it is very close to the foundation, I am thinking of having it removed to preclude any damage. Could you confirm an ID and make suggestions about removal?


If you can send pictures of your tree to me via e-mail I will try to confirm your neighbors' identification. Flowers and seed pods would be the most helpful photos, but since it does not blossom, we will have to work with pictures of leaves and leaflets as well as pictures of the whole plant showing its growth habit. Your local NMSU Cooperative Extension office can also help identify your mystery plant.

New Mexico locust is a reasonable plant to consider as a proper identification of your tree in some high elevation, higher moisture areas of New Mexico. It is a small tree, or large shrub, with leaves composed of small, roundish leaflets. When it flowers it produces attractive clusters of pink pea-like flowers. It is in the bean/pea family, so the flowers look like the flowers of beans and peas. It flowers early in the spring, so late freezes may kill the blossoms; however this is rather unlikely since it is native to New Mexico and well adapted to many higher elevation locations in New Mexico. It may just be too young to flower. If you pruned the tree in the winter or late summer, you may have removed the preformed flower buds. This would also explain the lack of flowers.

The New Mexico locust produces numerous "suckers", or sprouts formed from adventitious buds that develop on roots. This propensity of this tree to spread underground makes it less desirable than many other plants. In native plantings and for erosion control its thicket forming habit may actually be beneficial.

As a small tree or large shrub, it may be allowed to grow more closely to home foundations and sidewalks than larger trees. However, its thicket forming tendency may result in plants that are definitely too close to your structures. Removal, as you mentioned, or transplanting to another location may be a wise thing to do. Perhaps one of the sprouts formed from the roots is already growing in a more appropriate location. If you choose to remove the tree, you will need to diligently remove new plants as they form. Persistence will definitely be a virtue. Chemical treatment (appropriate herbicides) or physical removal (digging)are both effective management techniques. If you wish to use chemical management techniques, please contact your local NMSU County Extension Service office for information regarding the most effective and safest products to use. They can also advise you as to proper application methods. If you choose physical removal, the key is to remove the quickly as they appear by cutting them below the soil surface. If you delay in removing the sprouts you will make the process more difficult.

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.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

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