Roses The Straight Scoop Parts - care of roses in autumn

Flower & Garden Magazine, Sept, 2001 by Ann Hooper

THE STRAIGHT SCOOP PART 5

FALL CARE FOR YOUR ROSES

From cold and frosty, through inches and inches of rain, to big and little heat waves, with a microburst or two thrown in, it's been a challenging rose season. But roses are tough plants, and they've survived despite Mother Nature's wrath, rewarding the rosarian with plenty of color in the garden and lots of flowers for cutting.

Now that the gardening season is winding down, you'll find that it's the best time to enjoy your roses. The cooler weather makes flower color more vibrant, and because the buds take a longer time to develop, the blooms will be larger and more perfectly formed.

If you've fallen down on the job and haven't kept your roses insect, mite and disease free, it's still not too late to clean them up so they'll be strong enough to survive another winter's onslaught. A fungicide containing copper sulfate and mancozeb, such as Junction[R], will eradicate both powdery mildew and blackspot if you spray it once every 10 days for the remainder of the season. Kelthane, Avid or Floramite will eliminate red spider mites if it's sprayed once every 10 to 14 days. And Orthene will zap aphids, borers and other destructive insects that eat flowers and leaves. Japanese beetles--now they're another story.

In many parts of the country this year, Japanese beetles are running rampant. There are a number of controls on the market for Japanese beetles, but the truth is that there just isn't much you can do to keep them off your roses. They are so migratory that even if you destroy those that have invaded your garden today, more will just fly in from somewhere else tomorrow. I carry a small hand sprayer filled with Sevin into the garden every time I go out. Sevin will kill the beetles if you get it right on them, so I just give the tops of the plants a squirt a couple of times a day. You can also knock them off the plants and into a coffee can filled with soapy water. One dead beetle today is a couple dozen fewer beetles next season.

In the Midwest, cucumber beetles will arrive in August, posing the same problems for heartland rosarians as Japanese beetles do for most rosarians east of the Rockies. This corn rootworm beetle is not as sluggish as the Japanese variety, and they'll fly away before you can drown them in soapy water. Again, Sevin is your best bet.

Strong, healthy plants are the ones that survive winter, so if you get rid of the problems now, there's still time for defoliated plants to grow new leaves and throw out lots more flowers to delight your spirit. Be sure to deadhead religiously or cut the flowers to bring into the house. Don't allow the spent flowers to go to seed this early because hip formation signals the plant to slow down and prepare for winter.

Many varieties of roses, particularly those with large numbers of petals, are often at their most magnificent in late summer. If you like roses in the house--and who doesn't--cut as many as you can to make lovely rose arrangements or to give to friends. It's better that you enjoy them rather than the Japanese beetles.

Keep up your fertilizer regimen, applying chemical and organic fertilizers alternately. Most rosarians mulch their rosebeds to keep weeds at bay, but many of the materials we use can lower soil pH. Therefore, it's important to apply limestone as needed to ensure soil pH stays between 5.8 and 6.3 so the fertilizers break down into a state that the plants can use. Keep your rosebeds weed free, as weeds can steal the water and fertilizer that's meant for the roses. And water, water, water, if Mother Nature doesn't provide.

It's vital to keep up your watering, fertilizing and spray regimens, but your last fertilizer application should be a month or so before the first frost is expected in your Hardiness Zone. As you know, fertilizer promotes new growth and helps keep the plants' cells turgid. But as cool weather approaches, it's important to allow the plants to develop their own natural antifreeze. The plants' cell walls will thicken, which helps keep them from bursting during freezes and thaws. A broken cell wall is a dead cell, and dead cells mean dead canes.

As colder weather approaches and the plants' cell walls thicken, you'll notice that the canes turn purple on many varieties. At this point, you should stop deadheading and allow hips to form. It's probably best not to cut flowers, either, but if there's a beautiful one (or two or ten), by all means cut them. After all, why are we growing roses, anyway?

Cutting flowers or pruning back in the fall keeps the plant's sap running. It's like you're asking the plant to continue growing. This is not a good thing when you expect the plants to slow down, develop their own antifreeze and prepare themselves for winter. We'll discuss pruning and winter protection next time, but for mid-fall care, keep the soil moist and cut the canes as little as possible.

Temperate climate rosarians, of course, will have lovely roses well into fall, perhaps almost until Christmas. It's important, as well, for you to keep up your spraying, fertilizing and watering regimens almost until it's time to force dormancy. In warm climates, roses are itching to grow all year long, so it's important to force them to rest at the coolest part of the year. We'll discuss how to force dormancy in the next issue.