In the Central Valley of California, my roses and I are subjected to hot summer temperatures, which leave both of us a little worse for wear. This past summer it was over 100 degrees for 70 days out of the 90 days of June, July and August. I know. I kept track. The bad part is this: when it gets below 100 here, it's still in the high 90s. But this isn't a tirade about weather. It's about roses and fire ants.
In areas that experience mild winters like ours, fall is happily a season to celebrate another round of rose blooms.
In spite of the hot weather, my roses did the best of all my flowers. I watered them frequently and they did well. My irises, on the other hand, succumbed to the attack of fire ants before I could figure out what was going on. First I thought it was soft rot, but upon deep investigation it turned out to be millions of fire ants that were looking for water. They ate away at the corms and, next thing I know, little by little the exposed corms got soft rot and wilted away. Hot weather and moisture make a wonderful breeding ground for microbes. The ants were looking for water and the soft rot came in where the ants left damage. The nursery man advised: "Have another water source for the ants." For us this means put in that irrigation system sooner rather than later! Then the ants will have so much water they won't zero in on our precious flowers!
Now let's go back to roses.
There are a few steps to take to get them ready for their autumn show.
1. In late August through mid-September, lightly prune back the roses, removing up to one-third of their outer growth. This helps to remove sunburned leaves and stimulate new growth. Prune to an outward bud at a 45-degree angle. Clip off any diseased leaves.
2. Remove all rose debris, including fallen leaves, to help protect roses against being infected by any fungal diseases or damaging insects.
3. Apply rose fertilizer at the same time, working it into the top inch of soil around the root zone. Water well before and after applying the fertilizer to help ensure that it is well-distributed. Apply fertilizer for the last time no later than six weeks before the first average frost date for your area.
4. Apply a 2- to 3-inch layer of compost to help conserve soil moisture, prevent weeds, and add nutrients to the soil.
5. Deadhead flowers to promote the production of new roses through the fall.
6. Keep an eye out for any fungal diseases, such as black spot and powdery mildew, and treat accordingly.