Winter preparations for roses begin in the summer
Roses are beautiful shrubs in the landscape. Some gardeners prefer them in a formal garden all their own, but I would rather enjoy roses in mixed borders mingling with other shrubs and perennials.
Wherever roses are planted, they need some special care to make it through winter unscathed.
Winter preparations begin in summer. Healthy roses are best prepared for winter. Consistent watering throughout summer and fall, either by Mother Nature or your hose, is the first step. Correcting nutrient deficiencies and attending to insect infestations or diseases as soon as they are discovered is the next.
Roses are heavy feeders and require regular fertilization throughout the growing season. To help them ready for dormancy, cease fertilizing in mid-August.
Stop deadheading roses as blooms fade in fall and let them develop seed pods, called hips. This encourages plants to slow late-season growth more susceptible to winter injury.
After a few hard frosts and the leaves have dropped, apply horticultural oil to the branches, or canes, to kill pests and diseases aiming to overwinter on them. Be sure to remove all plant debris from under roses.
There are differing opinions on whether or not to prune roses before winter. I only prune out dead branches or those that seem vulnerable to breakage during heavy snows. I avoid hard pruning because it stimulates new growth at a time when roses should be channeling their energy into their roots.
If roses are very tall, branches can be tied together to prevent them from breaking in winter winds.
Once the ground has frozen, the goal of winter protection is to keep plants cold and prevent cycles of freezing and thawing. Mound at least a foot of top soil or mulch over the base of each rose. It is fine to use well-drained soil from other parts of the landscape, but don't risk damaging the roots of roses by digging nearby. Although this is especially important for grafted roses, I follow the same procedure with shrub roses, too. Better safe than sorry, right?
After the mound of soil or mulch has frozen, cover it with several inches of additional mulch, shredded leaves or evergreen boughs.
Styrofoam covers are not recommended for several reasons. First, roses must be pruned to fit inside them. Next, temperatures inside cones undergo extreme variations. Diseases may be triggered or new growth might be encouraged as heat and humidity build up on sunny days. Lastly, they are unattractive. White domes topped with bricks to keep them from blowing away does not a lovely winter landscape make.
In the spring as the ground begins to thaw, start removing the mound of protective material. If mulch was used, remove it gradually and carefully — a few inches at a time — to avoid breaking off buds just beginning to grow. If top soil was utilized, wash it away a few inches at a time with a garden hose.
The extra care to prepare roses for winter doesn't take much time or require special skills and is well worth the effort when roses wake up in spring healthy and ready to get growing.
• Diana Stoll is a horticulturist and the garden center manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield. Call (630) 293-1040, Ext. 2, or visit planterspalette.com.