Roses are tough plants when grown in well-drained soil, enriched with organic matter, and where there is good sunlight and air circulation. Fall is an excellent time to rejuvenate roses for a beautiful show of color before they rest for the winter.
“Roses welcome the relief of cooler fall temperatures. It is one of the best seasons for plant growth and flowering. With adequate watering, some fertilization and clean up, rose growers can enjoy many weeks of colorful blooms and help prevent overwintering disease problems next spring,” said Nelson Wynn, a regional horticulture agent with the Alabama Cooperative Extension System.
Prune any dead or diseased canes and spent blooms, especially those crossing into the center of the plant. Also, prune vigorous canes 1/3 inch above a five-leaflet leaf growing to the outside of the plant.
Continue disease and insect control sprays in the fall. “This is important to maintain healthy foliage, which is necessary to produce flowers. Tender new growth needs protection from sucking pests such as aphids, thrips and beetles.” Insecticidal soap is your first line of defense against aphids and sucking insects. A pyrethrin insecticide, Orthene or Sevin is recommended for control of adult beetles.
Fall is also a good time to rake out old mulch and diseased leaves that have shed during the summer. Nelson recommended replacing the mulch with 3 to 4 inches of clean pine straw. If you don’t have enough pine straw, use leaves shed from shade trees and top off with an inch or so of pine straw. The leaves will decay over time, adding humus to the soil.
Roses respond well to cooler nights and less humid days if you provide the moisture they need and one last application of fertilizer in early fall. If you used a complete fertilizer, such as 10-10-10 during the spring and summer months, only a small amount of nitrogen should be used. Wash any fertilizer off leaves and keep roses well-watered. An alternative would be to continue using a water-soluble fertilizer about every two to three weeks until six weeks before the first expected killing frost. This will allow roses time to begin their dormancy period before freeing weather arrives.