August 8, 2015

1 - Oleander plants are beautiful and easy to propagate from cuttings, but remember that they are toxic plants as you work with them.

Yard and Garden August 8, 2015

Q.

My wife has a miniature Oleander plant whose flowers are an odd peach color rather than the normal pink. We have been unable to find more like it. I was wondering if I might use some rooting powder and try propagating a number of starts for her. I have done it with roses before, though not always very successful in what I got, and I understand why with grafted plants. Anyway have you got any suggestions for propagating oleander plants?

-Bob N.

A.

I remember starting oleander plants from cuttings when I was a child in Southeast Texas. In that location all I did was cut some stems and put them in the soil in the garden and some of them grew. In New Mexico you will need to modify this somewhat because of the nature of our soil and our extremely dry air.

On several internet sites I have read of people taking stem cuttings 6 to 10 inches long from either the apex of the stems, or cuttings from the middle and basal portions of stems. They removed the lower leaves and trimmed all other leaves to about 1 inch in length. They then placed the cuttings in water or in a rooting medium (well-drained potting soil or perlite). Roots form quickly, but the plants should be allowed to develop a good root system before transplanting them. Roots formed on cuttings grown in water tend to be more brittle and more easily injured when transplanting, so you may have greater success by starting the cuttings in well-drained potting soil.

As you have experienced with roses, rooting hormone powders applied to the base of the cuttings encourages root development. Although the plants may root without the rooting hormone, the hormones are extra insurance of success. Because you may not have 100% success with cuttings forming roots, you can increase your probability of success by starting several cuttings and treating the base of each with rooting hormone.

Because of the very dry air in New Mexico, the cuttings will have a greater chance of success forming roots if you can maintain high humidity around the cuttings to prevent them from desiccating before roots form. You can do this by starting the cuttings in a greenhouse, or by creating individual greenhouses for each plant. You can put each pot with potting soil and cutting inside a plastic bag that is loosely tied closed or perforated with a few pencil holes. Do not put the plants in direct sunlight because these individual greenhouses will create individual greenhouse effects and cook the cuttings. A location with bright, indirect light will work best for the cuttings inside their humidity chambers. As roots form and net growth begins to develop you can increase the ventilation by making more holes in the bag, or by opening the bag more. This will reduce the chances for diseases and will begin to all the plants to acclimate to environmental conditions outside their humidity chamber.

A final important consideration is that oleander plants are toxic. The white latex (sap-like liquid) can cause dermatitis and even greater problems if it gets into your eyes. You should protect yourself with eye protection and gloves when handling the cuttings. Be sure not to ingest any part of this plant. They are beautiful plants and their flowers have a very pleasant fragrance, but their latex and toxins warrant cautious handling.

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:

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