Look for Good Foliage Healthy Roots on Tree

Question: I want to plant a tree in my yard. How do I go about choosing a healthy tree in the nursery?

J.M., Aliso Viejo

Answer: Take time when selecting a tree. Check the shape and structure of the plant. Does it stand straight? Does it look healthy and vigorous?

Tree foliage should appear healthy and absent of disease and insects. Don’t forget to examine the back of leaves as well.

Plant health is characterized by green to dark green color; relatively large leaves and dense foliage; smooth, bright bark (unless it’s a rough-bark tree) that is free of rot, galls, wounds and insects; and adequate shoot growth.

Select a tree that has not been headed back or topped, and which can stand without being staked. Once planted, a young tree may need to be properly staked during the first year or so.

The height and size of the canopy, which consists of the leaves and shoots coming from the upper portion of the plant, should be in moderate proportion to the size of the trunk and root mass. The trunk should also be tapered.

As for foliage, half should originate in the upper third of the trunk and the other half should be growing from the lower two-thirds of the trunk. This distribution balances the tree in the wind.

A healthy, well-developed root system is vital to the future of your tree, but is the most difficult aspect to examine when a plant is in a container. Generally, if the top of the plant looks healthy, the root system is also healthy.

It pays to inspect the root ball as much as possible. You can turn a one-gallon can upside down and tap it gently so the root ball falls onto a solid surface and then perform an inspection.

One method of removing two- and five-gallon size trees is to lift the tree out of its container by gently and slowly pulling on the trunk near the bottom, while also pushing down on the sides of the top of the can.

Ask the nursery for advice on other methods of removing trees from their pots. Try to determine whether the main roots are kinked or encircling the ball, as this can be a sign of being pot bound. Main roots can’t straighten themselves out, and your tree could eventually choke off its own growth.

Smaller roots will always encircle, because they are going toward the air at the edges of the pot, and can be straightened and pruned before planting. The smaller roots on an actively growing plant should have minute root hairs that on most plants will appear to be finer textured and white.

Some plants such as certain conifers, however, may be darker in appearance and plants such as bougainvillea have very sensitive roots that do not want to be tampered with at planting.

With some practice and advice from professionals, you will learn to distinguish healthy and vigorous trees from those that may fail or are already unhealthy.

Some nurseries will guarantee the health of your tree for one year, if it is planted properly. Ask about this consumer protection before you make your purchase.

--Written by University of California Master Gardener Pat Whatley of Laguna Hills.

Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or e-mail ucmastergardeners@yahoo.com. Calls and e-mail are picked up daily and are generally returned within two to three days.