During hot, dry weather there may not be enough water to go around, so you may have to set priorities.
It is important when you water to thoroughly moisten the soil to a depth of eight to 12 inches. In some cases a little is better than none, but when the soil has dried out to a considerable depth, a five-to-10 minute sprinkle with the hose is a waste of water.
It is easy to forget that a newly planted tree 10 feet or more in height will not become sufficiently established in two to four years. It will need watering during dry weather because the root system will not have spread far enough for it to go without water for long.
Shallow rooted plants such as dogwoods, azaleas and rhododendrons should be given high priority. These are the ones most likely to be killed or seriously damaged by drought.
The vegetable garden needs a thorough watering every week there is not at least an inch of rainfall. Frequent light waterings do more damage than good because they encourage shallow roots and will, inevitably, reduce yields. Shallow-rooted crops are far more susceptible to drought. A soil soaker is very good for the job.
When there has taken very little rainfall for three or four weeks, deeprooted trees and shrubs begin to suffer. A big tree cannot be replaced readily and should be given preference.
Mulching is very important for conversation of soil moisture. It also helps to control weeds which compete with other plants for water. Tree bark or wood chips are excellent for this purpose.
A tremendous amount of water is wasted watering lawns. The waste occurs when too much is applied too often or from frequent shallow watering, hose-in-hand.
Enough water should be applied each time (usually every week or 10 days during dry wether to wet the soil at least one foot deep. Then don't water again until the lawn shows signs of needing it (the lawn will turn a darker green and take on a slightly blue sheen, and in more advanced stages will lose its green color and take on a brownish cast).
Sprinkling the lawn for a short period with the hose is likely to do more harm than good. It brings the roots to the surface where they become quite vulnerable unless sprinkling continues every few days.
One way to determine the condition of the soil is to probe with a long shanked screwdriver. If the soil is moist, it can easily be pushed down to the ground .
Lawn grasses are shallow rooted in most gardens. Withfavarable soil conditions and proper watering, they are capable of going down 12 inches or more, and they have a lot of area to draw upon for moisture.
Vegetables such as cabbage and spinach may have root systems eight to 10 inches deep, beans about 12 inches, sweet corn about two feet, and tomatoes and asparagus three feet or more. However, in heavy clay soils, tomatoes and other plants have root systems less than a foot deep.
Normally, most trees have roots three to six feet deep, unless restricted by heavy soil or poor aeraction. Probably 40 per cent of the feeder roots are in the top one-fourth of the root zone. If the tree is surrounded by a vigorous ground cover, severe root competition will occur.