September 22, 2004 | By: Ellen Brightwell

Selecting ornamental varieties suitable to planting sites and transplanting them in the fall gives trees and shrubs a head start on winter and helps them provide pleasure and beauty for years to come.

For best results, choose ornamentals that are hardy to the area," said Rick Durham, Extension horticulturist with the University of Kentucky College of Agriculture. "Avoid trees and shrubs that are adapted to zone six or above because they are only marginally hardy in Kentucky."

"It is important to select ornamentals that are adaptable to environmental and soil conditions of the site," Durham said. "Talk to a professional if you are not familiar with the growing requirements for a particular shrub or tree or have questions about how to choose vigorous, healthy plant materials."

Planting an assortment of shrubs and trees will slow down the spread of disease and insect problems.

There are several reasons now through November is the best time to transplant trees and shrubs, Durham said. Ornamentals lose less moisture because fall days are shorter, outdoor temperatures are cooler and rainfall usually is adequate. These conditions also help retain soil moisture so plants can settle into the new location. Also, many of these plants are deciduous and lose their leaves in the fall so their demand for water is less.

"Whether you are adding new ornamentals, or simply moving existing specimens, planting them after the heat stress of summer will increase the likelihood of successful transplanting," he said.

Trees and shrubs also undergo internal changes that promote root growth and increase tolerance to winter weather. Leaf growth during the summer produced sugars that were moved into the roots, so ample energy is available to reestablish strong root systems after transplanting.

"Since woody ornamental root systems continue to grow at soil temperatures above 40 degrees, planting in October and early November usually will give them six to seven weeks before soils reach this temperature," Durham said. "Evergreen species retain their leaves during the fall and winter, so it is best to plant them in early spring, or perhaps early fall so root systems will have adequate time to become re-established before plant water demand increases.

Several ornamentals successfully can be planted in early to late fall, he said. They include coffee tree, crabapple, elm (disease-resistant varieties only) ginkgo, honey locust, linden, sugar maple, pagoda tree and serviceberry. It is best to wait until after leaf drop later in the fall to plant birch, flowering dogwood, oak, red maple, sweetgum and tulip poplar.

"Inadequate moisture during dry periods is the primary threat to transplant survival," Durham said. "Be sure to thoroughly soak the ground after transplanting. Frequently check newly-planted specimens to be sure the soil has not dried out. It is better to thoroughly soak soil once or twice a week than to water it a little every day. Providing sufficient moisture helps transplants survive adverse environmental conditions during the winter."

Durham said two common mistakes are choosing ornamentals that grow too large for the location and improperly planting them.

"A specimen planted with great expectations can grow into a headache when you have to severely prune to keep it away from the house, or the utility company must drastically cut it back to keep branches out of power lines," Durham said. "Be sure to dig a transplant hole that is wide enough. It should be at least two to three times the diameter of the root ball, even wider is better. A hole that is saucer-shaped is better than a bowl-shaped one."

Ornamentals should not be planted any deeper then they grew in a container or field. Use the soil line on the trunk to gauge how deeply to plant balled-and-burlapped ornamentals. A distinctive color difference on the trunk bark indicates how deeply a specimen was planted in the field. 
"If you are not sure how deeply to plant an ornamental, plant it on the shallow side," Durham said. "It is less damaging to plant a tree to shallow than to plant it too deeply."

After transplanting, apply a two- to three-inch layer of mulch. Avoid piling mulch around the base of the trunk because this may encourage rotting. A layer of mulch will help conserve soil moisture and discourage weed growth. Mulching also helps moderate soil temperatures that may cause the root system to heave out of the ground during winter freezing and thawing cycles.
He said not to fertilize newly planted trees and shrubs during the first year because it will cause excessive vegetative growth at the expense of root development. Also, amending the soil with sand, compost or peat moss is unnecessary and can keep an extensive root system from developing.

Durham said gardeners can find more information on home horticulture by contacting the local Cooperative Extension Service office and visiting the Department of Horticulture Web site.


Writer: Ellen Brightwell 859-257-4736 ext. 257
Sources: Rick Durham 859-257-3249