Weymouth, Mass. — Quite frequently during drought years when water restrictions have been in place, contrary to their expectations gardeners have harvested impressive crops of tomatoes. A typical comment might be: ``The plants were a little smaller than usual, but the crop was as good as I get in good years and maybe even better.'' Often other fruiting crops do well, too. Experiments indicate that when roots of fruiting plants are restricted (either mechanically or through lack of water away from the stem), vigorous vine growth is curtailed and more energy makes its way into fruit production. This isn't to suggest that dry seasons are a good thing for the garden, just that they don't have to be the restrictive experience we're led to believe.
A recent fall-like spell of drizzly weather in the Northeast brought a week's supply of needed moisture to gardens and farms in the region but did little to boost stream flow and raise reservoir levels. Weathermen tell us that only prolonged heavy rains will do that. At the same time, they also say that it isn't normal to expect this type of rain in summer. So the old axiom remains: Make every drop count. Gardeners in the Northeast or in any part of the country experiencing a water shortage might do well to count the drops. If they do, they should get by pretty well, even if their community is under restricted water use -- and they might even improve their tomato harvest.
Here are a few hints on water conservation in the garden:
When to water. If drooping occurs in the middle of the day, this is not necessarily a sign of overly dry soil. On the other hand, if plants droop in the cooler hours of the early morning or late evening, that's a sure sign that the soil is too dry for their needs.
Water deeply. This is a basic rule. Six consecutive days of sprinkling at a quarter of an inch at a time will do little more for the plants than keep them free of dust. In contrast, one soaking that provides 1 to 11/2 inches of water will keep a garden growing vigorously for one to two weeks, depending on the moisture-holding capacity of your soil. Usually, one to two hours of sprinkling is necessary. Check how much water is going to your plants by placing shallow cans here and there in the garden. When they contain an inch or more of water, turn off the tap.
Water early. If a sprinkler or hose is used, it is best to irrigate early in the morning, before sunrise if possible. This way, little water is lost to evaporation and the plants have time to drink deeply before the heat of the day arrives. In extremely hot, dry periods you may want to water in the early evening (generally considered unwise, as dampness combined with darkness favors mildew development), since the hot conditions will readily dry off the leaves without the aid of the sun. Of course, if you apply the water with a watering can or hose directly to the soil, then evening watering presents no problem whatever.
Water-saving options. Draw up a ridge of soil around the edge of all garden beds. In effect this dams the water, preventing it from running onto the path where it is not needed and forcing it to soak in around the roots. The same thing can be achieved with larger plants by forming a shallow, saucerlike depression in the earth around each one. Keep renewing these ridges, because they readily erode. An old auto tire around some plants does the same thing, and you can be sure it will never erode.
Another option is to punch holes in a can and sink it into the soil on one or two sides of a plant. By watering directly into the can, moisture will slowly be released into the surrounding soil. A variation on the theme is to stand a plastic milk jug full of water with holes punched into the bottom beside a plant. This allows the water to leak out over the root zone. Anchor the jug down by tying it to a short stake so that it will not blow away when empty.
Consider a rain barrel. Often, during hot, dry periods, a quick rainstorm will blow up and over in a few minutes, bearing little more than an empty promise in its clouds. This type of rain is frustrating for the gardener, as it merely wets the surface of the soil and does very little for the plants. But the roof of your house represents a significant water catchment area, and what runs off the roof during a fairly insignificant rainstorm can fill a barrel. A few of your plants, if not all, will be able to drink deeply from this supply. This approach saved many a garden in southern Africa and Australia during the devastating drought that gripped much of the Southern Hemisphere a few years ago.
Add a little shade and perhaps a wind break or two. In intense heat, partial shading benefits even sun-loving plants, and saves water by lowering transpiration (the way a plant perspires) through the leaves. While conventional shade cloth (available in 20 percent and higher ranges) is too shady for plants such as tomatoes, bird netting suspended over a frame can take some of the bite out of the sun.
Hot winds also dry out garden soils and step up transpiration rates. Windbreak cloth placed on a fence around the garden can do much to reduce wind velocity in the garden. Even old bed sheets can be strategically placed to lower the drying potential of the wind.
Mulch. Finally, always mulch your garden. This can dramatically reduce the frequency of watering. Back in the early 1960s, a citrus estate in then Rhodesia (now Zimbabwe) was unable to expand because of a lack of irrigation water during the dry season. Plans were made to raise the wall on the estate's only dam at considerable cost. At this stage, a new manager took charge and promptly had the groves mulched with elephant grass that grew plentifully in the area. This saved so much water that the planned expansion took place without adding an inch to the wall of the dam.