May 10, 2014

1 - Summer pruning roses by cutting flower to take indoors or to remove spent blossoms helps manage plant size.

2 - Non-toxic and low toxicity methods of managing aphids on garden transplants are possible.

Yard and Garden May 10, 2014

Q. #1

I never finished pruning my roses this spring. Between work, wind, and changing weather, I just did not get finished. Is it too late to prune them?

-K. M.

Albuquerque

A. #1

If it is absolutely necessary to prune them for safety or sidewalk clearance. If pruning is to remove dead, damaged, or crossing branches pruning now is advised. Pruning at this late date should be minimal pruning, not as extensive as usual spring pruning. The health and vigor of the rose plants must also be considered. Healthy, strong plants may be pruned more than weak plants.

Another consideration is that summer pruning can begin soon. Summer pruning of roses is pruning to remove spent flowers. Such pruning may be simple deadheading to remove just the flower and a small portion of the flower stalk down from the flower to the first 5-leaflet leaf as commonly recommended. However, in vigorous plants the stem may be cut back much more. Another form of summer pruning is cutting long-stemmed rose blossoms for indoor decoration. This allows you to remove a large amount of the excess growth. This may be the pruning you are considering at this late date. You need only wait until the roses flower and then remove the flowers with long stems. Just remember to use proper pruning techniques.

Q. #2

My chile and tomato transplants growing indoors on my window sill are covered with aphid insects. I prefer not to use poisons, but I do not want to lose my transplants. What are my options?

-Mary J.

Taos

A. #2

There are some organic insecticides and other materials that are toxic to certain insects, but not toxic to others and not toxic to humans. Read the labels carefully to determine if you want to use such products. You should contact your local NMSU Cooperative Extension Service office for information about which products may be useful.

Insecticidal soap is an example of the products that can be safely used indoors. However, these products may harm fabrics in the home, so protect upholstery, curtains, and floor coverings if you use it indoors.

Plain water can also be helpful to wash the aphids and some other plant pests from the plants. This may not eliminate the pests, but may reduce their numbers enough to allow your plants to survive until you can plant them outside.

Once the plants are outside, non-chemical methods may be sufficient to reduce the population of pests until natural biological controls take over management of your problem. There are numerous insects that will feed on the aphids and help manage your problem. Use of broad-spectrum pesticides on plant pests outside may actually kill the insects that will kill the pests. The use of water to wash the pests off may be your best treatment for aphids on plants outside.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook page.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!