Limit fall pruning of New Mexico roses

I know I have read this before, but I cannot remember if it is ok to prune my roses in the fall or if I should wait. When is the correct time to prune roses in New Mexico?

K.K.
Santa Fe

Answer:

Prune roses in the late winter or early spring. A useful guide is to prune your roses approximately two weeks to one month before the date of the last expected spring frost in your part of the state. I use this guide because that date varies greatly across our state. Southern New Mexico gardeners can prune roses as early as Valentine's Day while in Santa Fe you should wait until sometime in April (depending on your specific location and elevation). Further north and at higher elevations, gardeners should wait even longer.

There is a good reason for waiting. Most of our modern roses (hybrid tea, floribunda, and grandiflora roses) do not actually go dormant in the winter. If the weather remains warm, they will continue growing and flowering in the winter. They only stop growing when the weather is cold enough to stop the roses' growth. Pruning can stimulate growth at the wrong time. Another consideration is that the buds you will leave after pruning are "protected" by the buds above them. These buds (that will be pruned away) will begin growth first if the weather stimulates growth too early. These early buds inhibit growth of the lower buds. If growth begins too early, the buds that will freeze are those that you will remove when you prune anyway. However, if you prune too early and a mid-winter warm spell stimulates growth, the buds that will freeze are those that you are depending on for growth later in the spring.

There is what seems to be an exception to this rule. In the autumn, you can trim and tie long branches that are subject to damage by winter winds. However, do not cut them back to the point that you will in the spring. You should leave some "sacrificial" buds to begin growth early if unseasonable weather stimulates early growth. This maintains the natural protection mentioned above, yet lets you do some of the work ahead of time and protect your plants from winter damage.

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.

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