Issue: August 3rd, 1998

It's ok to summer prune damaged branches

The storms have damaged some of the larger branches in my trees. Big branches have broken. I know you are not supposed to prune them in the summer, so when can I prune out the broken branches?

While we recommend not pruning large branches in the summer, that recommendation is for healthy branches which are contributing to the health of the tree. The damaged branches you described are a liability to the tree. You can prune dead, dying, or damaged branches in the summer. It is important to remove the damaged branches by careful pruning to prevent them from doing further damage to the tree by ripping the bark down the trunk (if that has not already happened).

Some people may prefer to try to repair the damage by supporting the broken branches so that they may form a graft connection at the point of the injury. This may be successful if done immediately, but the chances of success rapidly decline over time. If you choose to attempt repair grafting, be careful that you do not do more harm than good. I have seen trees with ropes and chains around them as an attempt to hold a splitting trunk or to hold up a broken branch. Such treatment can girdle the tree and damage more than the broken branch. Some people use a large bolt placed through the branch and the trunk. This requires drilling a hole in the undamaged part of the tree and, if successful, results in steel being enclosed in the tree, creating a hazard many years in the future when someone with a chainsaw may be cutting the tree. At that time it may not be known that there is steel in the tree and the chainsaw operator may be injured. So, use caution if you wish to "repair" the tree.

Proper pruning techniques are shown in many gardening magazines and books. Be sure your source of information is recent since pruning techniques have changed in the last couple of decades. If the bark has been torn down the trunk, it will be necessary to clean up the ripped bark, but again it is important to do less damage than the original injury to the tree. In some cases, professional help will be required. Just be sure that the tree care professional has remained current in his field and continues to upgrade his knowledge by attending conferences, self-study, and courses taught at accredited colleges and by the Extension Service. Check out his work by asking for references just as you would if you were hiring a contractor to do major work on your home. The trees are a valuable part of your investment in your home.

Weeds taking over

Since the monsoon rains have come to New Mexico, the weeds are taking over. What can I do?

It is too late now to use pre-emergence herbicides to control the warm season annual weeds, but you might plan for them next year. These are herbicides which do not injure established plants if they are used properly but will prevent new seed, weed seed, from germinating and creating new plants. Check with your local County Extension Agent or professional nurseryman for the proper products to use under your conditions.

Now that it is too late for these herbicides, mechanical control, mowing and weed removal, or use of post-emergence herbicides are your best options. If you choose the herbicides, be certain to use one which will affect the weeds you wish to kill without harming the desirable vegetation. Some weeds may be controlled by mowing, but others must be removed. The key is to prevent them from forming seeds if they are annuals. Perennial weeds present their own special problems. Consult with your County Extension Office or Garden Center experts to identify the weeds and determine your best options. Remember to plan ahead to next year to control the annual weeds which can return again only from seeds.

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 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!