Issue: January 29, 2000

Pruning a young tree

I have a 4-year-old fruitless mulberry tree. We have been pruning it for the last couple of years by trimming it way back. We want it to grow up and out to provide maximum shade. When is the best time to prune it? We normally do it around this time, but I'm not sure if that's right. How much should we be taking off?

Now is a good time to prune deciduous trees. Major pruning is best done during the dormant season - after leaves have fallen in the fall and before growth resumes in the spring.

A young tree should be pruned only to train it. Remove as little wood as possible. Your term "cutting it way back" makes me think you may be pruning too severely. However, without seeing it and not knowing what "way back" means to you, I can't say that you are pruning incorrectly.

Regrowth from severe pruning occurs at the expense of the tree's protective mechanism. Pruning reduces tree growth and reduces the tree's ability to survive environmental, insect, and disease stresses.

You should prune to remove branches which are positioned too closely together on the trunk. Remove branches that are hazards or will create hazards in the landscape - those which are too low or are growing toward structures.

In even young, vigorously growing trees, do not remove more than 30 percent of the twigs which will bear leaves in the spring. In a young tree that may mean you can only remove one (or a few) large branches which will have many twigs on them. Older trees should be pruned less. If your 4-year-old tree is healthy and growing vigorously, then you may prune up to the 30 percent mentioned above. If it is not growing vigorously and does not appear healthy, prune less than 30 percent or not at all.

Contact your local Cooperative Extension Service or their associated Master Gardeners for more detailed information and publications on pruning.

Early garden planting

The winter has been warm here in New Mexico. Does that mean I can plant my vegetable garden early this year?

The fact that the winter has been relatively warm thus far does not mean it will stay that way. Extremely cold, damaging weather has occurred in late winter and early spring in the past.

If you are anxious to plant early, watch the weather forecasts and consider using some of the devices designed to protect plants from cold weather. There are a number of effective devices available on the market, and home built devices are described in many gardening books. If you do choose to plant early, be prepared to replant later if the cold weather does develop late this year. Location in New Mexico determines how early you can try to get a jump on the season. Of course, southern New Mexico has the earliest opportunity for starting the garden and the northern and high elevation parts of our state require later starts, whether starting at the normal planting time or whether risking an early end to winter.

It is fun to start early and to have early harvests, but there are definitely risks to consider when doing so.

Send your gardening questions to Yard and Garden, ATTN: Dr. Curtis Smith, NMSU Cooperative Extension Service, 9301 Indian School Road, NE, Suite 112, Albuquerque, NM 87112. Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist with New Mexico State University's Cooperative Extension Service. New Mexico State University is an equal opportunity/affirmative action employer and educator.