Certain petunias tolerate heat
Q. Is it too late to plant more zinnias? With the rain, I let the weeds overtake my present planting and they have declined.
A. No, it is not too late. Go ahead and plant transplants. We have four more months of good zinnia blooming weather left.
If you want to lengthen the bloom season of the bud, you could also consider the hardy petunias such as Wave, Laura Bush, or VIP. They can tolerate the August heat, plus prosper until very cold weather occurs in January.
Q. Is it time to plant tomatoes for the fall? What varieties are best?
A. Late July and early August is a good time to plant tomato transplants for fall production. Use the heat-setting varieties such as Surefire, Heatwave, Sun Pride, Solar Fire, and Dwarf Cherry Surprise (BHN 968) as the most likely choices to beat the cold weather. It is also good to include Tycoon, Celebrity, Merced, and 444 in case the cold weather extends into December.
Q. Is it time to fertilize my Bermuda grass? After two tough drought years it is finally looking good again, and I want to keep it in good shape.
A. If the Bermuda is subjected to heavy use and water is available, it is sometimes fertilized in the summer, but for most lawns, the May 1 and October 1 fertilizations are plenty.
Q. Yesterday I was outside clipping the dead blooms (hard green balls) off my crape myrtles to encourage new blooms and I noticed one of my three trees lining my back fence didn’t look so good. As you can see from the pictures, there is some black stuff on the leaves. Additionally, this tree hasn’t really produced many blooms lately. The leaves feel coarse and with fairly little pressure, some of the black will rub off. Do you have any idea what could be causing this and how to treat it?
A. The black coating is sooty mold caused by a fungus growing on excrement produced by aphids feeding on the crape myrtle leaves. The aphids may already be under control by predatory insects. The aphids can be sprayed with an insecticide like Spinosad or Safer soap but they usually run their course quickly. The sooty mold will gradually wear off the leaves and the plant will begin blooming again.
Calvin Finch is a horticulturist and the San Antonio Water System’s director of water resources. Hear him on “Gardening South Texas” on KLUP 930 AM radio Saturdays noon to 2 p.m., and 1-3 p.m. Sundays. Or, email him at firstname.lastname@example.org.