New roses at base could mean plant’s roots are showing

I will be conducting a class on growing peaches in Southern Nevada on June 17 from 2-4 p.m. and again from 7-9 p.m. The class is free of charge and is intended to encourage small-scale production of peaches, as well as backyard growing. I will be covering which peaches have done the best for us at the University of Nevada Cooperative Extension Master Gardener’s demonstration orchard, proper planting, watering and fertilizing, as well as pest control.

The class will be held at the Lifelong Learning Center, 8050 S. Maryland Parkway, Suite 100, will require no registration or reservations. For more information, please contact me at morrisr@unce.unr.edu or call 257-5555 and speak with a master gardener.

Q: I have 28 rose bushes in my garden and about one-third of them are giving me a problem that I have never seen before. I have an assortment of colors and the strange thing is that some of them are getting deep red, small roses from the bottom of the plant up. This is happening on my white, yellow-orange and other colored roses. What can I do before they take over all my roses?

A: These red roses are most likely from the rootstock and should be removed. The most common rootstock for garden roses is Dr. Huey, a red rose. Dr. Huey is also a climbing rose, which may explain its vigor.

Many commercially grown roses are a blend of two roses; one is grown for its root system and the other is for its floral show. The two roses are joined together in a horticultural technique called budding. A bud of a rose with desirable flowers is joined to the root system of another.

The rootstock imparts some very desirable characteristics to the top, or the floral parts, of the rose. If the top of the rose grows vigorously, it keeps the rose acting as the rootstock under control. It stays as a root system and does not produce shoots or flowers.

When the rootstock is no longer under the control of the top, then shoots can grow from the rootstock and produce flowers. Usually flowers from the rootstock are not as desirable, but the flowers of Dr. Huey aren’t bad.

On the rose plant you will see what is called a “dogleg,” where the two roses are joined together. In older roses the dogleg may appear as a large knot. Nothing should be allowed to grow from below the knot or even from the knot itself. All growth must come from the part of the rose above the knot or the rootstock rose will begin to take over the plant.

The usual reason for the Dr. Huey rose to begin growing is that the top was pruned too close to the knot or union of the two roses. It also is possible that insect or disease damage could cause the top rose to die back significantly, thus releasing its hold on Dr. Huey. Remove all growth from the knot and below it. If you cannot without destroying the entire rose, then dig it out and replace it.

Q: I planted a dwarf peach tree a couple of months ago. It had lots of blossoms at the time, so now it has lots of small peaches. It’s been dropping about one peach per week. Is that anything to worry about?

A: There is a normal drop by most fruit trees when they set too many fruit for the tree to support. In order for a fruit to be supported by the tree, the tree needs to provide around 40-70 leaves per fruit. The leaves supply carbohydrates (sugars primarily) as energy for fruit and tree development. If there are too many fruit and the tree cannot support that many, excess fruit will drop. It is not a good idea for a newly planted tree to carry a lot of fruit. Having lots of fruit slows down its establishment and future productivity.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at morrisr@unce.unr.edu.