THE SECRET of a good vegetable garden is good soil. For a better garden next year, plant a cover crop of annual rye this fall. In the spring, plow or dig it under. It helps improve all soils, and particularly those predominantly clay or sand.

In addition, the cover crop reduces the amount of soil lost during winter by splash erosion and surface runoff. Splash erosion is due to the impact of raindrops on the soil surface. Each drop, falling as a tiny projectile, breaks small particles from the soil mass, and these then are removed by surface runoff during heavy rainfall.

Grass plants are among the best natural soil conditioners known. They produce an extensive system of small roots that thoroughly penetrate the soil.

Before seeding the rye, spread ground limestone and 5-10-5 fertilizer at the rate of 8 pounds per 100 square feet and mix them with the top six inches of soil. This will get lime and phosphorus down into the root zone for next year's crops. Apply 2 or 3 pounds of annual rye per 100 square feet.See VEGETABLES, Page 3, Col. 1 From the -Ground Up VEGETABLES, From Page 1

Apple scab and cherry leaf spot overwinter on the fallen leaves of apple and cherry trees. Raking and removing all of them will help reduce infection of new foliage next spring.

To help control fruit rots and insects that attack apples, peaches and plums, destroy all fruit that has fallen to the ground and remove fruit mummies from the trees.

The iris borer (pink caterpillars) hatch from eggs laid by moths in the fall on old iris leaves and nearby debris. Pull off the old leaves, rake up any debris and put it all in the garbage can.

Organisms that cause hollyhock rust live over winter on old leaves and stems. They should be cut off and removed from the garden.

Cut off the stalks of peonies and remove them from the garden. Make the cut with a sharp knife about one-fourth of an inch below the soil surface. This helps control botrytis blight of peonies, which causes flower buds to turn brown or black and fail to open.

Powdery mildew is one of the worst pests of phlox and zinnias. The disease organisms survive the winter on the dead tops. Cutting them off at the ground level and getting rid of them will remove a source of infection in the spring.

Dead rose canes should be cut off and removed. Tall stems that might be whipped around by winter winds should be shortened to keep them from loosening the roots in the soil. Piling up soil around them for winter protection may do more harm than good.

Water lilies growing in small pools can be protected with a covering of boards topped with a thick layer of straw or leaves.

If the pool is too large to be covered with boards, draw off the water and cover the water lilies with leaves. If they are growing in water deep enough not to freeze to the bottom, they need no protection.

Evergreen trees and shrubs growing in containers should be moved into a garage or basement where temperatures range between 35 and 40 degrees Fahrenheit.

Q. How long does it take to make compost? Is there a chemical that can be used to speed it up?

A. Warm temperatures hasten decomposition, and the length of time depends on the method and time of year. With a compost bin and an activator, it is possible to have useful compost within six weeks. The activator is nitrogen fertilizer, which is food for the bacteria that cause breakdown of the material.

Q. I have a snake plant with a flower on it, and nobody believes it when I tell them about it. Is it something very unusual?

A. There are about 34 different species of Sanaevieria and all of them have been known to bloom. The ones that bloom are the ones that get good care. During the growing season, give them good light, water them every week or 10 days and, during the winter, water only about every three or four weeks.

Q. I've been told rubbing alcohol is good to use to get rid of insects on house plants. Is it?

A. Rubbing alcohol is a very efficient wetting agent, or surfacant, that penetrates an insect's waxy protective coating and carries the pesticide into contact with the insect's body. Mealy bugs are very susceptible to alcoholic preparations. Insecticides used with the rubbing alcohol should be emulsifiable concentrates because tests haven't been run on wettable powders in alcohol. Caution should be used in handling alcoholic insecticides. Alcohol may carry poisons to the human body as effectively as to an insect.

Q. Can you give me some advice on curing and caring for gourds?

A. Make sure they are mature before harvesting. Put them in a dry place with good air circulation for four or five weeks, handle carefully to avoid scratches and bruises. Mature gourds will resist your finger nails when you apply pressure to them.

Q. I have a very frustrating problem with cucumbers and squash. The vines of the cucumber were loaded with tiny cucumbers and one after another of them wilted and died. The same thing happened to the squash. Do you know what the trouble is?

A. It is due to a small caterpillar called the squash vine borer which attacks squash, pumpkin, gourd, cucumber and muskmellon. Moths lay eggs on stems and leaf stalks the young caterpillars tunnel into the stems to feed, the plant wilts and dies. Dusting with methoxychlor powder may save the plants. Follow directions on the label for application.