There’s no need to rush outside to prune your roses, but now would be a good time to prepare for that annual process.
Start by identifying which of your roses are Old Garden Roses, and which are modern roses. The OGRs are once-bloomers, growing on their own roots, while modern roses, e.g., hybrid tea roses, are repeat bloomers, grafted on sturdy rootstock (often ‘Dr. Huey’).
There are numerous rose species, varieties and hybrids, but pruning methods differ greatly between the two broad groups: OGRs and modern roses. Briefly, OGRs bloom on old wood and are pruned in the late summer, after their bloom period and before they set buds. Generally, prune OGRs in a limited manner, removing no more than one-third of the bush.
In comparison, modern roses bloom on new wood, and are pruned more extensively during the winter months, before new stem growth and buds appear in the spring.
Modern roses are hybrids, typically with species that evolved in Asia, where winters are not harsh, so dormancy is related more to winter’s shorter days than to its lower temperatures. In the Monterey Bay area’s moderate climate, modern roses can continue to grow through the winter months without a period of deep dormancy.
Still, even a relatively light dormancy gives modern roses an important rest period, and pruning during this period promotes new stems and large blossoms.
This year, despite December’s record-setting warm spells, we can rely on short winter days to enable our roses to enter dormancy. Defoliation (stripping a rose’s leaves) encourages that process and reduces the potential for continued top growth.
With that background, prepare to prune your modern roses at any time during January or February. The basic techniques have been described and illustrated many times in books and websites, so rather than providing a capsule version of those techniques, I have listed print and online resources on my website, ongardening.com, for your reference.
I will repeat my recent suggestion to relocate your roses, as needed, during the same period. Prepare the new location by digging a hole two to three times as wide as the root ball you expect to have, to support horizontal root growth. The new hole should be only as deep as the existing root ball, to minimize settling of the transplanted rose.
We ready to transplant the rose soak the new location thoroughly. Then, soak the existing rose, lift a good-sized root ball from the bed, and plant it in its new location at the same level as it was in its old location. Water it in.
Now is also the time to select bare-root roses for your garden, so next week I’ll review rose selection and buying.
There are many websites with good, free information about pruning roses. Search for “pruning roses” to see several options. Here are some that I found helpful:
American Rose Society (scroll down to the articles on “Pruning Roses”)
If you would prefer a book, look for these more general pruning titles in your local library or bookstore:
Pruning Made Easy – How to Prune Rose Trees, Fruit Trees and Ornamental Trees and Shrubs, by H.H. Thomas (2013)
This book will be published early in February 2014:
Pruning Made Easy – The Complete Practical Guide to Pruning Roses, Climbers, Hedges and Fruit Trees, Shown in Over 370 Photographs, by P. McHoy