Rose Bush Calendar of Maintenance in the Desert

Q. I planted a rose bush facing south as a memorial for my Dad and I want to know how to help it along. It has holes in some of its leaves and a few yellow leaves. I saw one grub and I got some stuff to get rid of grubs. 

A. Roses in a southern exposure have not had many problems provided they stay healthy. 

Select a Good Variety First-Off

Varieties of roses suited for desert environments handle hot locations well and may bloom throughout the entire winter if planted in the right microclimate. Like all roses, they don’t flower well during the heat which may start a month early (May) in southern exposure is like yours. List of desert roses.

Aphids heavily feed on roses in the spring during cool weather before the flowers open. They start early and are aided in their transport from rose to rose by ants.

Look at Your Rose Often

            Look at the color of the leaves and the quality of its new growth to judge its general health. New growth should be vigorous and the leaves dark green. These are two signs the plant is healthy and growing. Hopefully, you amended the soil at planting, then use organic mulch on the surface of the soil surrounding them, fertilize them three times a year and water when they need it to keep them healthy.

Even though leaf cutter bees damage rose leaves and petals, I like them. You can encourage leaf cutters with 1/4 to 3/8 inch holes drilled in 4x4's. The females use the holes for laying eggs. They are solitary bees, not social bees like honeybees so they don't need a hive.

Disease and Insects

            In dry environments like ours, roses have few disease problems and insect problems are rare, mostly occurring in the spring. We may see aphids and flower thrips in the spring and occasionally cane borer but it’s nothing to be alarmed about. You will handle these problems when you see them. Grubs feeding on the roots in the spring may occur and a systemic insecticide drench applied around the roots once a year will take care of them, and aphids, at the same time.

This isnt rose but it doesn't matter with leaf cutter damage. They always make the same size and shape holes in soft leaves and flower petals.

            The size, shape, and position of holes in the leaves tell you a lot about which insect may be causing this. Most commonly it is leaf cutter bees. We may see the same damage on vegetables, basil, and other plants with soft, tender leaves. The strategy is the same. We leave these insects alone. They are good pollinators and so we choose to live with that kind of plant damage and understand its meaning.

This isnt rose but iron chlorosis looks the same. Its always on the newest leaf growth and gets worse the newer the leaf. The available iron has been limited for awhile. In the spring, soil applications of iron work. In summer and fall you will have to spray iron on the leaves multiple times to get it to work. So get your precautionary iron soil application done early.

Nutritional Problems

            As far as yellow leaves go if they appear on older, bigger stems, ignore it. If these yellow leaves occur and new growth in full sunlight then we may need to look a little deeper on why.