Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, March 14, 1991 TAG: 9103190132
SECTION: LAWN & GARDEN PAGE: LG-8 EDITION: METRO
SOURCE: By CHARLES STEBBINS
DATELINE: LENGTH: Medium
Things don't grow right. Plants are stunted, leaves curl at the edges and get reddish-purple or yellow, fruits are small.
"It means the nutrients in the soil are not available to the plants," said Jacqueline S. Brown, a horticulture technician with the Virginia Tech Extension Service. "The nutrients are tied up in the soil," she said.
A pH gone wild does not mean nutrients are lacking, she said. It means they are in a form in which the plants cannot use them.
This means the soil is ill, just the way people get sometimes. If not ill, then sickly and undernourished.
Sickly soil produces sickly crops. And to continue growing crops in sickly soil continues to drain the soil of its limited nourishment.
Soil tests can head off those kinds of troubles. Tests, at $6 each, can be obtained from any Virginia Tech Extension Service office, which can supply a box for the soil sample along with instructions.
The extension service recommends soil tests at least every three years.
But most home gardeners don't get soil tested as often as they should. And fortunately, nature pretty well takes care of the situation.
Soil tests, among other things, measure what is referred to by the initials pH which means potential hydrogen. It is a measure of the acidity and alkalinity of the soil.
A pH of 1 is very acid and 14 is very alkaline. Seven is neutral, and it is at that point and one or two points lower that most crops grow best. A few plants will grow in a pH of 4 or lower but nothing will grow in soil with a pH of 8 or higher.
Most plants do best in a pH of 7 (neutral) or about 6.5 (slightly acid). Some thrive in 4.5 pH soil, including blueberries, azalea, laurel, rhododendron and most broad-leaf evergreens.
A range of 5.5 to 7 is the range for most vegetables, berries, fruit trees, flowering trees and lawn grasses.
Soil tests determine not only the pH of soil but also the level of its other nutrients, such as nitrogen, phosphorus and potassium /potash.
All of these deficiencies can be cured with applications of various elements, either organic or chemical. Soil test results make note of what is needed to correct deficiencies.
by CNB