Get your roses in shape for another season

4/14/2010

If you have roses in your landscape, you'd better get busy. This is the perfect time to get them revved up for the summer blooming season. Pull off those winter rose cones when you see the forsythia blooming and get the pruners ready when the daffodils are sprouting. And you'd better keep the aspirin handy, because you have a lot of work to do around the yard!

"Now is a good time to plant bare-root rose bushes, amending the soil to a sandy loam or use a good potting mix, not a potting soil, and water new bushes," says Cheryl Menard of Maumee, a member of the Toledo Rose Society.

Roses are big eaters, so fertilize now with amendments with the numbers such as 5-10-5, 10-10-10, or 12-12-12 to encourage bloom strength. Ms. Menard says, "Most garden retailers locally have a pre-mixed rose bush fertilizer for your convenience. I like to mulch my rose bed with very small (fingernail size) pine mulch to maintain moisture all spring and summer. If you spray your rose bushes for fungi, start early to get ahead of the fungus."

If you have a pair of heavy gloves on and pruners in your hand, before you hack away you need to know what you are doing with those tools. Always prune the rose canes at a 45-degree angle about one-fourth inch above an outward-facing bud. This will help the new buds face outward. The center of the cane should look white. Get rid of anything that looks diseased or damaged. Clean your pruners with alcohol between each cut just to be sure you aren't spreading disease from one shrub to the next. If part of the stem has turned dark green or black, cut back to the bright green wood.

Remove any branches that grow toward the center of your bush to open the area to better air circulation. Then go after the canes that cross each other, pruning out the weakest ones. Suckers along the base of the plant also need to go. If you have hybrid teas, grandifloras, and floribundas, keep their canes 12 to 24 inches long. Get rid of all old canes, leaving the nine to 12 healthiest.

Climbers need to have the spreading buds clipped to help them produce more blooms. Cut them back, leaving four or five buds. The oldest wood can be removed at the base to encourage new growth.

Toledo reader Barbara Levison says she planted four knockout roses three to four years ago. "Up to last year they all were doing well on the west side of my house, blooming beautifully, until something attacked my leaves. So far this season, one rose bush looks good - leaves sprouting all over. The second bush has only one green cane while the other canes appear brown. The last two bushes are dead. What do you supposed happened?"

The two dead bushes are beyond help. Dig them up and examine the roots. Look for grubs and damaged or swollen roots. It is possible that the shrubs are in hard clay and not able to expand into the soil around your planting bed and may have gotten too wet.

Cane borers are also common with roses. They will go right down the center of the straw-like rose cane and lay their eggs. Once they hatch later in the season, the larvae eat their way out of the cane. A large enough population can kill the plant. Usually you will notice the plant wilting, with yellow foliage and dropping leaves. Ms. Menard and other avid rose growers have a secret weapon in their garden apron while pruning.

"Seal all cuts with Elmer's Glue or Tacky Glue. This helps prevent rose cane borers from entering." You can also use tree wound paint, wax, or nail polish. Another trick is to add a drop of food coloring to the glue so that you can tell which canes you have treated.

It could also be a bad case of spider mites, Ms. Menard says. "A herd of spider mites can desecrate a bush in one day. Telltale signs that they are attacking is that [the plant looks like something is sucking all moisture out of [it]." Look for tiny webs under the leaves; the mites like to spread from one bush to the other. Spray water under the leaves in the morning, then look for spider mite insecticides from your favorite home and garden store.

Diehard rose growers and novices too should stop by a Toledo Rose Society meeting on the fourth Tuesday of each month at 7:30 p.m. in the Toledo Botanical Garden Conference Center.

Contact Kelly Heidbreder at:

kheidbreder@theblade.com