Roses: the straight scoop part 6 winter care for your roses - gardening

Flower & Garden Magazine, Nov, 2001 by Ann Hooper

A rose is a rose is a rose, and rose plants are grown very similarly in all climates. Winter, however, is a different story. No matter where you live, roses need to rest during the winter months. In warm climates, they have to be forced into dormancy. In cold climates, they'll go dormant all by themselves, but they have to be protected from winter's wrath. So how you handle your roses during fall and winter depends on where you live. * Let's start with cold climates, since winter is nearly upon us and cold climate rosarians have a little more work to do to keep their roses snug during the coldest part of the year.

* FOR ROSES GROWN IN COLD CLIMATES

Where winters are cold, and there are extended periods of below-freezing temperatures, roses are vulnerable to damage, or even death, by cold winds and the cycle of freezes and thaws. The object of winter protection for roses is not to keep them warm--believe me, I've made that mistake--but to keep cold, dry winds from desicating the canes, and to keep the vulnerable bud union from being damaged.

Like other living things, plants are made up of cells. During the growing season these cells are turgid. But like the hardy perennial plants they are, roses have their own natural antifreeze that kicks in as the days get shorter and the soil and the weather get cooler. You can often observe a purpling of the canes as winter approaches, which means that the cell walls are thickening in preparation for winter's onslaught. At this time, you should stop deadheading spent flowers and allow hips to form--another signal to the plant that it's time to slow down and prepare for cold weather.

Because cutting flowers and pruning rose canes signal the sap to run and the plants to grow, it's best not to cut rose canes at all during mid and late fall. Of course, if there are some really beautiful flowers you want to cut, do it. After all, that's why you're growing roses in the first place. But don't cut rose canes unnecessarily. In fact, you really shouldn't prune rose canes at all in the fall unless they are so long that they'll whip around in the wind.

Before you do anything to protect your roses, allow them to go dormant. In most northern climates this will be in November, usually around Thanksgiving, after cold weather arrives, but before the soil freezes to any great depth.

About the time you're ready to winter protect, or a week or two before, is the time to move any roses you've decided should be in a different place. Prune the canes back to a foot or so, and dig up the plant to include as much of the root system as possible. Move the entire root ball to the new planting spot, plant as usual, and mound the entire plant with soil. By the time you uncover your roses in the spring, the transplanted rose will have been working for some time to make new roots, so you can expect it to grow and bloom normally the spring after transplanting.

Many rose insects and diseases can overwinter on rose plants and on debris in rosebeds, so make sure your plants are insect, mite, and disease free and all fallen leaves are picked up before you apply any winter protection materials. A spray with Bordeaux Mix, Orthene, and horticultural oil will zap all the worrisome insects and diseases, and will help the plants defoliate.

Most of the leaves on your roses will fall off on their own, but it won't hurt anything to leave the stubborn ones on the plant through the winter. However, the leaves on the lower part of the canes should be removed so they don't rot under any protection materials you intend to use.

Some types of roses, and even some varieties of roses of the same type, are more susceptible to winter damage than others. If you've grown roses for a long time and know that your varieties will survive winter with minimal damage, don't do a thing differently. But if you have new plants or if they've suffered severe damage in previous winters, you'll want to protect them.

The most vulnerable point on most rose plants is the bud union--the point at which the rose variety was budded onto a rootstock. The bud union is the "knob" at the base of the cane from which all new canes grow. Most modern roses are budded, and have a bud union, while heritage roses, many shrub roses, and most miniature roses grow on their own roots and do not have a bud union. Own-root plants are generally hardier than budded plants, but some protection will ensure their quick recovery come spring.

Whether your rose plants have a bud union or not, winter protection is best and most easily done by covering the base of the plant with a mound of soil. In most cold climates, you should expect that every part of the cane that is not covered will suffer damage or necrosis, which has to be pruned off in the spring. So the deeper the soil mound, the more of the cane will survive. Remember that cold climate rosarians will want to prune their modern roses, especially the hybrid teas, fairly low in the spring anyway, so it's not necessary to cover the canes from top to bottom.