Issue: April 19, 2008

Should I trim lower leaves from tomatoes when planting?


Question:

Do you have to trim the lower branches off of a tomato before you plant it or can you just plant it?

 

Answer:

I suspect you are asking if the lower leaves should be removed from the tomato stem when you plant tomatoes. Tomato plants have leaves with large petioles and many leaflets, so these leaves look much like stems. However, they cannot grow any further because they are leaves and have no buds. If you are planning to plant the tomato plants deeply (tomatoes can form roots along the stem if it is buried), then you should remove the leaves. However, this is not critical. If the leaves are buried, they will not be able to photosynthesize, so they will be of no benefit to the plant.

If you have very large tomato plants that have actually begun to grow branches (with buds to allow continued elongation), then you may leave them if the growing point will be above ground after you plant them. If these stems will be completely buried, they are probably better removed to make sure that no disease enters the plant as these stems decay.

In other regions of the country, removal of secondary branches even above the ground is recommended. This results in earlier, fewer, but larger tomato fruit. In our extremely high light conditions, this may result in sunscald damage to the fruit because removing stems removes leaves. In New Mexico, the greater number of leaves on the plant (due to additional stems) provides shade to protect the tomato fruit from our intense sunlight. For this reason, I do not prune the secondary stems from my tomato plants.

 

Prune lilacs, forsythia, and other spring blooming shrubs after flowering.

Question:

 

In last week's column you said that now was the worst time to prune trees. Is this true for shrubs? I have always pruned my lilacs after they flowered.

 

Answer:

Thank you for allowing me to continue this discussion. By maximizing the loss of stored food needed for plant growth, spring pruning can cause problems for many trees and shrubs. However, pruning early spring blooming plants in the winter removes their flowers (the reason we grow these plants). The lilacs and forsythias are examples of plants that are usually pruned in the spring after flowering. This pruning should only be to remove spent blossoms to prevent them from forming seeds. More extensive pruning than this will be more debilitating. However, when it is necessary to prune for safety reasons, proper pruning techniques and pruning only as much as needed will minimize the negative effects of this pruning.

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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:

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

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

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