Wait for warmer soils to plant palms

By Angela O'Callaghan

Tuesday, Nov. 25, 2008 | midnight

Winter in Southern Nevada is not the dreary season that it is in other parts of the world. Here, gardeners are able to make plans and get interesting plants into the landscape most of the year.

Palms are the exception; they need to be planted when soils are warm. With this notable exception, many native plants will tolerate being placed in cool (not cold) soils. If the soils have been properly prepared, and the hole is the right size, they have a good chance of survival. The right size hole is three to five times as wide as the root ball and no deeper than the container. Because desert soils are generally low in fertility and not easy to work with, the addition of a small amount of compost is generally a good idea. About 5 percent compost in the fill will provide nutrients and aid drainage.

Desert trees tend to be shrubby, which means that they have multiple trunks and grow about as wide as they do tall. It is not uncommon to remove some of the trunks and only allow three or four to grow, giving it less of a "bush" appearance. Certain trees, like some members of the ash family, will grow into a stately landscape addition and often have only one trunk.

Whatever landscape tree or shrub is planted, it is a good idea to think of the plant not as it arrives from the nursery but as it will appear in 10 or 20 years. Gardeners can occasionally be victims of their own success.

Several popular ash trees, such as Arizona, Fan-Tex and Modesto, will be elegant and stately but may ultimately reach a height of 50 feet and a width of 30. Many people enjoy pine trees like Aleppo and Mondel but might not be prepared for the mature plant as it grows far beyond 30 feet tall. Even if height is not an issue, remember that a tree's root system will extend beyond the width of the canopy. This can cause problems when they are planted close to structures.

Not all trees grow rapidly of course; some ashes take many years to reach their full size. Large pines are generally categorized as fast-growing, however.

Smaller trees are the most likely to be shrubby. Even so, they can be exquisite and many are relatively slow to reach their full size. Lately, I have become very fond of a few of these – their foliage is lovely and their flowers would make anyone happy.

Texas mountain laurel will only finally reach a height and width of 15 feet after quite a few years. It produces a splendid display of purple that looks like wisteria and smells somewhat like grape. Texas olive produces gorgeous white flower clusters and oval leaves. While it might reach 25 feet by 25 feet, this will not happen quickly.

Trees of all sizes enrich a landscape, but they are most welcome when they fit well. Thinking about the mature size will help the plant to always be enjoyable.

Angela O’Callaghan is the area specialist in social horticulture for the University of Nevada Cooperative Extension. She can be reached c/o the Home News, 2360 Corporate Circle, Third Floor, Henderson, NV 89074, or [email protected].