Native Plants

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Sunday - October 11, 2009

From: Las Vegas, NV
Region: Rocky Mountain
Topic: Diseases and Disorders, Pests, Transplants, Trees
Title: Failure to thrive of pecan trees in Las Vegas NV
Answered by: Barbara Medford

QUESTION:

In April this year I purchased two 8-foot tall pecan trees in 3-foot square boxes from a local nursery and planted them here in Southern Nevada. I'm sure I dug a large enough hole to provide plenty of room for roots to spread. The soil is somewhat alkaline. I mixed some root stimulant and organic compost into the soil at planting. Through the hot summer, I've gone to great effort to assure the trees were frequently and deeply watered and I used drain pipe buried around the trees to be sure the soil was getting deep saturation. The trees seemed to do very well at first, including many branches of new growth. Unfortunately, as the hot weather set in around June, the leaves started turning brown at the edges until completely brown, dead and brittle, although they did not fall off the tree. The browning of the trees progressed from the top downward. The upper branches also appear to be dead or dying. One of the larger branches broke off in a recent wind storm, showing both brittleness and a sort of dry rot with tinges of powder at the break. There also appears to be some cankers with reddish brown dust in the bark on the main trunk. Now in October, one tree has only some sprouts of leaves at the base of the trunk near the ground. It looks like it is certainly a goner and the other may soon follow. I've had pecan trees grow successfully on other properties in Southern Nevada before, so I know it's possible. Any suggestions for my current Pecan tree problems?

ANSWER:

We are so sorry to hear about your trees. Carya illinoinensis (pecan) is not native to Nevada; in fact, the nearest state where it is native is Texas. Here are the Growing Conditions for this tree from our Native Plant Database:

Water Use: High
Light Requirement: Sun
Soil Moisture: Moist
CaCO3 Tolerance: Low
Cold Tolerant: yes
Soil Description: Rich, moist, well-drained soils. Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay, Caliche type
Conditions Comments: The sweet, edible nut, makes pecan the best hickory for fruit production. The tree does not bear liberal quantities of fruit in the northern part of its range, but makes an interesting ornamental there. Susceptible to galls, twig girdlers, aphids, borers, weevils, pecan scab, tent caterpillars, and webworms. Slow-growing. Difficult to transplant because of a large taproot.

Some of the things that occur to us from these Growing Conditions are that it is a difficult tree to transplant because of the taproot. Also, it is susceptible to many pests and diseases. There is always the possibility that there were already some problems with the trees that had not become apparent when they were purchased. It sounds like you did everything you could to protect the trees from the conditions in your area. We are not plant pathologists, and could not begin to diagnose the problem from a distance. We suggest you contact the University of Nevada Extension Office for Clark County. They may, in turn, recommend you have a trained, licensed arborist look at the trees, as do we. If there was pre-existent damage or disease, you might be able to get your money back from the retailer where you purchased the trees.

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Sunday - October 11, 2009

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