March 16, 2013

1 - America's favorite garden vegetable, tomatoes, can be a challenge to grow in New Mexico's heat.

Yard and Garden March 16, 2013


What is the secret to growing tomatoes in hot, hot New Mexico? I have failed three years in a row.

M. Marshall



There are several problems that can influence your gardening success in New Mexico. Tomatoes are America's favorite home garden vegetable, but it can have problems in New Mexico. One common problem is the variety grown. Some tomato plants do better in New Mexico than others. The varieties that produce the largest fruit are often the most difficult to grow. Cherry and pear tomatoes often produce fruit when other varieties fail to produce.

Soil conditions can also be a factor. A soil with too much nitrogen fertilizer will result in excessive growth with no fruit production. Extremely high levels of mineral salts (native to the soil, water, or from over fertilization) can cause problems.

There are several insects and diseases that cause problems. Perhaps the most common problems of this type are curly top virus and tomato spotted wilt virus. Both are spread to tomato plants by insects. However, insect control is not the solution in this case. The viruses overwinter in weeds and are spread by insects from the weeds to the tomatoes in the spring. Weed management is the best solution to the problem.

As you mentioned, the heat can cause problems. While proper variety selection can help, there are other factors and treatments to consider. Heat results in more rapid drying of plants, so proper irrigation is important. Our bright sunlight combined with the heat can also cause problems. Many New Mexico gardeners have learned that by shading their garden, their tomato and other vegetable crops are improved. Some gardeners suspend wooden snow fence to provide about 30 percent shade. Other gardeners use shade fabric (30 to 50 percent shade). A light-colored fabric will reflect sunlight from the garden without re-radiating heat into the garden, so choose a white or other reflective shade fabric. Shading helps in many ways, reducing heat, reducing water loss, blossom-end rot, protecting from hail, providing some frost protection at the beginning and end of the growing season, and a more pleasant gardening environment for the gardener.

Your local NMSU County Extension Service Agent can help you determine which of these factors are considerations in your garden and help you find a solution that results in success.

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:, office: 505-865-7340, ext. 113.


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

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at, or at the Desert Blooms Facebook page.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!