Gardening columnist Tim Daly answers the following questions from readers:

Question: The leaves on my roses have been chewed up and are brown. What has caused this problem, and how can it be corrected?

— Alice, Norcross

Answer: Alice, your roses have been attacked by rose sawfly larvae, which have a small, green slug-like appearance. They hatch in the spring and attack the leaves of roses by chewing holes in them. This year has been particularly bad for the pests.

By now most of the insects have finished feeding and are gone. If the plants are healthy, they will recover. In the future, carefully observe the roses during the spring, and if the rose sawfly larvae are found, apply an insecticide labeled for control.

Q: I planted several rows of bush beans in my garden. Recently I noticed holes appearing in the leaves, several orange round beetles and some small yellow spiny organisms on the bottom of the leaves. What are these bugs, and what can I do to reduce their presence?

— James, Buford

A: James, you have an infestation of Mexican bean beetles. The adults are small, round, and orange in color with black spots. They resemble and are closely related to the beneficial lady beetles. The spiny yellow organisms are the larvae of the beetles.

Both feast on the leaves, thus reducing photosynthesis that causes less bean production. For control, apply Sevin or another insecticide labeled for control of the insects. If you are reluctant to use pesticides, you can smash them with your fingers, though the process is labor intensive.

Q: I have purchased several small trees, shrubs and a few perennials. Is now a good time to plant them with the temperatures being so hot? Is so, what should I do to the plants before then?

— Joe, Snellville

A: Joe, with the heat and dry conditions, you should wait until the fall to plant them. Place them in a site with part shade and keep them watered. Of course, you could put them in now, but their chances of surviving are significantly lower.

Autumn is the ideal time for planting because the cooler temperatures allow for them to become established better. During the winter, the top parts will grow very little, but the roots will continue to expand. The plants will be more resistant to the hot, dry conditions of the following summer. Make sure you keep newly installed plants watered thoroughly to improve their ability to become established.

Keeping our home landscapes healthy and attractive can be somewhat challenging with the heat and dry weather. UGA Extension in collaboration with the Gwinnett County Department of Water Resources will be offering a class on Water Wise Landscaping from 6 to 7:30 p.m. June 13 at the Buford One Stop Center, located at 2755 Sawnee Ave., Buford. To register, contact the Gwinnett County Department of Water Resources at dwrworkshops@gwinnettcounty.com or 678-376-7193, Option 5.

Timothy Daly is an Agricultural and Natural Resource Extension Agent with UGA Extension Gwinnett. He can be contacted at 678-377-4011 or tdaly@uga.edu.

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