Issue: July 5, 2008
You can prune roses some in the summer
I live in Las Cruces, and purchased a home that has some roses along a north wall. They are quite tall and I wanted to know when to prune and down to what height? Is there a website I can visit to get more information?
Roses should be pruned in the late winter or very early spring. The optimum time-window for rose pruning is the period from one month to two weeks before your expected last frost. Even when pruned at this time, an abnormal late freeze can do considerable damage to your rose plants, but it is unlikely.
Now that it is summer, pruning is not forbidden. Dead and weak branches may be pruned away. Old rose plants often have such growth on the inside of the plant. It is difficult to prune the interior branches at this time, but some may be pruned away now. Long branches that have broken in the wind may be pruned as soon as they are broken (or later if you have left them). Finally, the best summer pruning is the taking of long-stemmed roses to enjoy indoors and pruning away the spent blossoms. When cutting flowers or removing the spent blossoms, cut back at least as far as the first leaf with five leaflets. In the autumn, as the outdoor temperatures cool, you can trim back very long rose stems to prevent damage from winter winds (and ice for gardeners in colder regions of New Mexico).
Next spring (for those of you in Las Cruces, about St. Valentine's Day) you can do the major pruning. At this time you can prune hybrid tea, grandiflora, and floribunda roses to a height of 18 to 36 inches. More severe pruning results in fewer, but higher quality flowers. Climbing roses should be pruned less. And shrub roses pruned only to remove the dead and weak branches.
More information regarding rose pruning is available in the publication H-165 Growing Roses at the NMSU College of Agriculture web site http://www.cahe.nmsu.edu/pubs/_h/H-165.pdf.
Many New Mexico communities have active garden clubs and some have rose societies with certified rosarians. You can learn a lot by attending the garden club or rose society meetings.
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: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!