Selecting Sites

In selecting sites for gardening the most important factors are sunlight, air circulation, protection, competition from trees and large shrubs, drainage, soil structure, and soil fertility.

Most fruit trees and vegetable plants require direct sunlight most of the day for optimum growth and productivity. Some leafy vegetables will tolerate partial shade, but fruit trees and fruit-producing vegetables need direct sunlight. Most plants can tolerate some shade from buildings, fences, and distant trees, particularly during the late afternoon, and some may even benefit from such shade during the hottest part of summer in warmer regions of the country.

Air circulation is important in reducing the likelihood or severity of plant diseases which affect leaves and fruits, particularly in humid areas.

Prolonged dampness of foliage following rains or heavy dew favors development and spread of fungus and bacterial diseases that affect plants. Too much shade, especially during the early morning, compounds the problem.

Windbreaks may be beneficial in certain parts of the country, such as the Great Plains, to protect plants from strong prevailing winds. For fruit crops in particular, "frost pockets" should be avoided, since good air drainage helps reduce the hazard of late spring frosts.

Protection from certain animals is often desirable. A close-woven fence around the garden may be needed for protection against rabbits, dogs, and other animals. A fence can also serve as a trellis for crops such as tomatoes, cucumbers, and pole beans. Other types of protection may be needed in some areas against rodents and animals such as mice, moles, ground squirrels, and prairie dogs.

Avoid competition from trees and large shrubs so far as possible. The ill effect of too much shade has already been discussed. Moreover, tree roots often extend considerable distances from trees and will compete with garden crops for moisture and plant nutrients. Cutting tree roots along the edge of the garden will usually provide only temporary relief, since the tree roots will again extend rapidly into the fertile, moist soil of the garden area.

Soil drainage, structure, and fertility can usually be improved. A loamy, fertile soil with a medium clay subsoil is ideal. The structure (and fertility) of heavy clay soils can be improved by adding liberal quantities of organic matter such as compost or manure as well as lime and fertilizer. The fertility and moisture-holding capacity of very sandy soils can be improved in a similar manner, except that less lime should generally be used than on heavy clay soils.

A soil test should be taken as a guide to how much lime and fertilizer are needed.

Good drainage also is important, since plant roots must have air as well as moisture. Adding organic matter improves the moisture-air balance in most soils. However, if your garden site is subject to flooding or has poor surface drainage, you may be able to improve the site by installing drain tile, digging drainage ditches, or plowing deep into the subsoil to breakup an impervious layer called a "hardpan".

If you encounter this problem, seek professional help and advice from your county extension agent, the Soil Conservation Service, or a drainage contractor.

Are street lights near the garden beneficial? Usually not. Are they detrimental? Usually not. However, some vegetables such as spinach, lettuce, cabbage, and radishes are sensitive to daylength or "photoperiodism" in that they tend to "bolt" or go to seed when days are long and temperatures are warm. Thus, street lights can, in effect, create longer days. But most vegetable and fruit crops are not sensitive to daylength. Street lights close to the garden may be beneficial as a security measure against thefts or vandalism.

Preparing Soil for Planting

Soils vary widely in different areas of the country. Ideally, the kind and amount of commercial fertilizer and lime should be applied in accordance with soil test results. Your county Extension office or local garden center can assist you with respect to taking soil samples and sending them to the nearest soil testing laboratory for analysis.

Lime, when needed, has a fourfold effect on most soils:

1. It adds calcium, magnesium, and certain other plant nutrients, depending upon the kind of liming material used.

2. It reduces soil acidity, thereby making some major and minor plant nutrients more readily available (or soluble) for plant growth.

3. It improves the physical structure of heavy clay soils;

4. And it improves the environment for certain beneficial micro-organisms in the soil, including those which decompose organic matter, thereby releasing nitrogen and other nutrients for plant growth Organic matter has a highly beneficial effect on most soils. It makes soil more "mellow" and, when it decays, releases nitrogen, minerals, and other nutrients for use by plants.

There are those who advocate the use of organic matter to the complete exclusion of chemical fertilizers to improve soil fertility and productivity. On the other hand, modern technology makes it possible to supply all the nutrient elements needed for plant growth in the form of commercial fertilizer. Most organic materials do not contain a "balanced ration" of all the nutrient elements needed by plants. Thus, organic matter will not Supply all the nutrient elements needed to correct deficiencies in many Soils, the sandier ones in particular. Accordingly, the wiser choice in most cases is to use both organic matter and chemical fertilizers in quantities needed for optimum productivity.

Organic materials such as compost and livestock or poultry manures can be mixed directly into the garden soil. However, undecomposed materials such as tree bark, sawdust, leaves, lawn Clippings, straw, and refuse from the garden or kitchen should be composted before mixing them into the soil although they can be used as a surface mulch around plants.

Here's why. Humus (decayed organic material) has a carbon/nitrogen ratio of about 10 to 1. Wheat or oat straw has a carbon/nitrogen ratio of about 70 to 1, and the ratio is much higher for woody material such as sawdust and bark. The decomposition process requires large quantities of nitrogen, and plants will suffer from nitrogen deficiency if substantial amounts of undecomposed organic material is mixed in the soil during the growing season.

Sawdust as mulch

When used as a mulch on the surface, however, the organic material can be turned under at the end of the growing season, in which case extra nitrogen fertilizer should be added to speed up decomposition before the next growing season. If, during the next growing season, plants develop nitrogen deficiency (become yellow and stunted in growth), it can usually be corrected by moderate applications of nitrogen fertilizer as needed during the growing season.