Pensacola News Journal

For: Saturday Feb. 2, 2002

By: Daniel E. Mullins

Extension Horticulture Agent

Santa Rosa County

Two Simple Tools That Make Gardening Easier

What is your soil’s temperature today? How much rain has your lawn received within the past 2 or 3 days? Some of the better farmers and gardeners could quickly respond to both questions because the answers have a direct influence upon several cultural practices. There are inexpensive tools for monitoring both soil temperature and rainfall.

A soil thermometer can be used to accurately measure the temperature in any area of the landscape. Soil thermometers are available at some garden supply outlets and from horticultural specialty suppliers.

The standard soil thermometer is made for exposure to the elements and can be left outdoors or in a greenhouse in order to obtain constant readings. I purchased one several years ago. It had a 4 inch probe, which is long enough for most situations.

The probe was placed 3 inches deep in a perennial bed by the back door. It was located near the house so that I could check it early in the morning and then again in late afternoon when returning from work. The radial dial is easy to read and the soil temperature can be checked with a glance.

Readings obtained from this soil thermometer has provided some valuable information. Most surprising was how greatly temperatures fluctuate during the day. In early spring, morning temperatures within the top 2 inches are often in the low 50s, followed by mid-afternoon temperatures in the high 80’s.

Most spring planted flowers and vegetables don’t germinate or grow well until soil temperatures stabilize above 68 to 70 degrees F. The monitoring of a soil thermometer reveals when wide fluctuations cease and conditions are most favorable for planting.

The roots of permanent warm season lawns, such as centipede and St. Augustine grass, like flowers and vegetables, don’t begin to grow and function well as long as soils are cool. Fertilizer, if applied too early, is therefore wasted or is used to stimulate unwanted early weed growth. A soil thermometer can help take the guesswork out of correctly timing the spring fertilizer application.

A rain gauge is another recommended tool. Though a simple device, it can be of great value in helping to determine when and how much to water the lawn, flower bed or vegetable garden.

Most rain gauges are very inexpensive. They are normally made up of a clear tube or tapered cylinder with marks that show how much rainfall was caught since it was last emptied.

The placement of a rain gauge is very important. It should be located in an open area, where no branches, leaves or other structures can interfere with exposure to natural rainfall.

Following are some rules of thumb for irrigation based on rain gauge readings. About one-half inch of rain or irrigation is enough for established lawn grasses and flowers on sandy soil. If the gauge shows that a half-inch or more of rain has fallen, then no irrigation will be required for several days.

Established shrubs and vegetables require more water at each application, but less often than flowers and lawn grasses. If the gauge shows that at least three fourths of an inch of rain has fallen, then there is no need to irrigate for several days.

The use of a rain gauge, in addition to helping save water, is useful in determining rainfall patterns in your neighborhood. Daily monitoring and seasonal rainfall data helps the gardener to develop more efficient use of gardening time.

Question of the Week: When should I fertilize my azaleas?

Answer: Wait until late winter or early spring. If fertilized too early you could stimulate them to grow too early.