Often the application of a little extra moisture avoids stunting or slowing of plant growth by preventing plant tissues from hardening. The added moisture may be small in volume but, because it comes at a critical time during the growing season, often makes the difference between a good garden and one that is at best mediocre.
A private well is a fortunate solution to watering problems. The well need not be elaborate. A driven pipe with a pitcher pump can supply all water needed for emergency irrigation in most areas. Electrical or gasoline-driven pumps are not expensive and will ease the pumping chore.
DOMESTIC WATER SUPPLIES
Sometimes untreated ground water is too loaded with undesirable salts to be usable. Here the gardener must depend upon local municipal sources for water other than that supplied by rain. The first thing I did when I bought my present home was to order 200 feet of 3/4-inch copper pipe, which is cheap, durable, easy to lay and will withstand some freezing even if not properly drained. Placement of water taps at convenient intervals allows me to quickly sprinkle the entire back yard if necessary. I am fortunate in having a 11/4-inch copper pipe to the street, which gives me plenty of pressure. If you are building or repairing your house, I recommend that you have that size of pipe installed.
AN EARLY START
Except for my Merion Kentucky bluegrass lawn, which does better if it is run slightly dry, I don't wait until soil dries out before I start irrigating. Rather than allow the accumulated moisture of spring to pass off, I start applying water as soon as we go for a week without rain. I then turn on the sprinklers and keep them running until the soil is moist six inches down. Of course, that does not mean I have put on an overall six inches of water: in a true Gardener's Loam the organic matter provides many pore spaces throughout the soil mass that trap air in little bubbles. Many of these pores are so small that water bridges over them by surface tension and does not enter.
I find that when I apply 22/1 inches of water, as measured in coffee cans set at intervals, moisture will have penetrated approximately six inches. Every gardener should check the water intake capacity of his soil by actually measuring how much water penetrates to what depth. With experience you can learn to judge moisture by feel. Once you have felt your soil when it is in good tilth and adequately supplied with moisture, you will be able to judge the condition of the soil by merely picking up a handful and giving it a squeeze or two.