Learning to prune roses perfectly is a little like learning how to bake bread. It takes practice but over the years, you figure out how to do it just right. And even when it’s not perfect, it’s still awfully good.
Pruning roses is part art, part science. The most important part is probably timing. Each spring, about the time the crocuses are blooming in late March or early April, Iowa roses need to be pruned.
Why? Pruning gets rid of unsightly and disease-attracting dead wood and also trains the rose to grow in an attractive, uniform manner. Without pruning, a rose bush will become a tangled mass of canes (branches) that crowd and rub together, inviting disease and cutting back dramatically on bloom.
Lower-growing bushy roses, such as hybrid teas, shrub roses and floribundas, are pruned differently than climbing roses. Here we focus almost solely on the bushy roses, which are certainly the most common in Iowa where only a few super-hardy cultivars of climbing roses will grow.
The best way to learn how to prune roses is to do it. You’ll be a bit bewildered at first, but after doing it for a few years — and seeing that your roses will hardly give up the ghost because you made one false cut — you’ll gain confidence and skill. And maybe even have fun.
Decide When to Prune
Prune roses in early spring when they first send out tiny red buds, which will turn into shoots, then branches. These buds let you determine what existing wood is live. Plus, the direction that the buds grow will help you decide where and how to make cuts.
Remove Dead Wood
If there’s any mulch or soil mounded around the base of the rose, push it away gently. Then cut away any obviously dead wood — wood that is thoroughly blackened and splintered.
Sometimes, making a tentative cut will help you figure out whether the wood is live or dead. Dead wood is brown and pithy, often with a hollow core. Live wood is green or white and firm. A branch often will be dead at the end but live farther down. In this case, cut down at least to the live stuff.
Shape the Rose
The goal is to achieve a pruned rose bush that has three to seven short, thick (at least as fat as a pencil) branches, evenly spaced, curving outward from the center in a vase-like shape.
Pruning branches in this manner encourages them to grow strong and away from each other and avoids rubbing branches or a congested center — both of which encourage disease.
If your finished product falls short of this ideal shape, don’t despair. Many roses, especially after a hard winter, don’t lend themselves to this ideal. Some hardly have enough live wood to even shape. Just do the best you can with what you have
When making the final cut at the end of a branch, make sure that it is just above an outward facing bud — the little red leaflet positioned to grow away from the center of the rose. Make the cut at a 45-degree angle, sloping inward toward the center of the bush. This discourages fungus-causing moisture from staying on the cut end and encourages new growth upward and outward, keeping a nice open center on the bush.
Roses grow and bloom best with frequent feedings. In Iowa, feeding once a month March through August is ideal. (Don’t fertilize after that; it will just encourage new, tender growth that will get zapped by winter cold.) A feeding right after pruning will encourage a shot of new, vigorous growth.
The easiest way to feed roses is to work in a slow-release granular fertilizer (organic or not) at the base of the rose. Some fertilizers even have a systemic insecticide to keep aphids, thrips, and other pests at bay.
ROSE PRUNING TIPS:
- Know if your rose blooms on old wood or new wood. If you know the name of the rose, check online. Otherwise, observe from one year to another.
- Most lower, bushy roses will bloom only on new wood, that is, new branches grown that year. On the other hand, many climbing roses and some antique roses bloom only on old wood, so you need to leave a lot of the wood from last year for them to bloom on. If in doubt, cut back the rose anyway. If it doesn’t bloom, next year give it only a light haircut to tidy it up a bit and see if it does indeed bloom on its old wood.
- Use a bypass hand shears, rather than an anvil-type shears. They crush the stem, inviting in disease. And make sure the blade is sharp. Either take the shears to a scissors-sharpener or sharpen it yourself at home with a tool file, available at better equipped garden centers.
- For larger rose bushes have a pair of long-handled loppers on hand. Shears usually can handle branches only up to 3/4 inch or so. Loppers can handle fatter branches found at the base of the rose.
- How far back you cut will depend on how large you ultimately want the rose. As a rule, cut roses that grow smaller shorter; cut taller roses taller. To keep a rose bush smaller, cut the canes to just 8 to 24 inches. Taller rose bushes can be cut as high as 3 feet. Climbing and other roses can be cut as high as 4 or 5 feet.
- No need to dab lipstick, wax, glue or anything else on the cuts. The latest research shows rose cuts heal best when left alone.
- In the fall, it’s OK to cut back very tall roses so the canes don’t whip in the wind. But as a rule, avoid pruning roses after they fully leaf out.
- Tough, close-to-the-wild rugosa roses really don’t need any pruning, other than getting rid of dead wood or canes that rub together badly.
l Veronica Lorson Fowler is co-publisher of The Iowa Gardener website at www.theiowagardener.com.