January 21, 2012

The time for pruning roses varies across New Mexico because of the variation in the expected date of the last freeze.

Yard and Garden
January 21, 2012

Q.
When is the proper time to prune roses in New Mexico? I live in Las Cruces and have heard various dates discussed.

Mary J.

A.
I have heard Valentine's Day suggested for rose pruning in Las Cruces. This is a convenient way to remember when to prune the roses, but it only works in your area. Gardeners in other parts of New Mexico must wait until later in the season before pruning.

A more general guideline to determine when to prune roses is to consider the expected last date of frost for your location, then back up one month. As you get closer to the last frost, the chance of a freeze that damages the new growth on the rose is lessened. If it is still cold, the new growth is delayed, so by the time new growth develops, the chances of a frost that can damage the new growth is minimal (but not impossible). The expected date of last frost at your location may not be the same as the date for the last frost in other parts of your county. Elevation and orientation toward the sun also play an important role. If you have experienced frosts when your local weather forecast is for warmer weather, delay pruning and other gardening activities that require freedom from freezing temperatures. Your experience at your site is the best guide as to the last frost and proper timing for rose pruning. If you are new to your location, your local NMSU County Extension Service office can give you some general information regarding last frost in your part of the country.

Many gardeners are concerned about pruning roses after new growth has begun. When you prune roses at the right time, there is often much new growth on the plants. Do not let new growth on the plants tempt you to prune too early. This new growth is causing the buds at the base of the plant to remain dormant. These buds nearer the base of the plant are the ones you want to provide the growth and flowers. If you prune too early, you may stimulate growth in these important buds. This growth may then be damaged by a late freeze. The growth in the top of the plant can be sacrificed to a freeze or pruned away without harm to the plant.

For more information, visit the NMSU Extension publications Web site at http://aces.nmsu.edu/pubs/_h, or to read past articles of Yard and Garden go to http://aces.nmsu.edu/pubs/periodicals.html.

Send your gardening questions to:

Yard and Garden, Attn: Dr. Curtis Smith
NMSU Agricultural Science Center
1036 Miller Rd. SW, Los Lunas, NM 87031

Curtis W. Smith, Ph.D., is an Extension Horticulture Specialist emeritus with New Mexico State University's Cooperative Extension Service. NMSU and the U.S. Department of Agriculture cooperating.