4. Check soil moisture. Dig down 1 foot with a trowel or spade and feel a handful of soil. An even easier way to test moisture is to use a sampling tube to "read" the soil. When you push the metal tube into the ground and twist it back out, it extracts a 12-inch or longer core, showing in cross section how wet or dry the soil actually is. If the top 2 inches of the soil sample are dry, it's time to water. Sampling tubes are available from [XREF "http://www.forestry-suppliers.com" "Forestry Suppliers"] (from $40; 800/647-5368).
5. Irrigate slowly. Slow soaking limits runoff and encourages plants to develop deep root systems that are better able to tolerate drought. The heavier your soil, the more important slow soaking is in preventing runoff. Using an oscillating sprinkler to water large areas helps reduce runoff. But if you see puddling, turn the water off for an hour, then start again. To minimize evaporation, irrigate in the early morning or evening.