Norman A. Plate
Believe it or not, it's possible to use more water on your summer garden than you use for all other purposes all year long. But you don't have to. Just be smart about when and how you water, and you'll have a lush landscape and lower water bills. Here's how to do it.
Annuals and perennials
Use soaker hoses or a regular hose set for a slow soak. Underground sprinklers with pop-up risers work in extensive flower beds, but risers should be tall enough that foliage doesn't block the spray. Choose drip emitters for beds with closely spaced plants and individual emitters for widely spaced plants. Avoid overhead watering, which can cause flowers to spot or droop.
Hand-water gently with a wide nozzle, or use drip to irrigate pots or hanging baskets. When you repot, choose glazed or plastic containers instead of terra-cotta, which is porous and evaporates water through its sides. Or slip a pot into a larger one, with a layer of sand between the two to shade the inner pot and slow evaporation.
Use hose-end sprinklers (best for small lawns) or underground sprinklers attached to a controller. Apply an inch of water per week (measure sprinkler output with an empty tuna can set on the grass). If water runs off before the can is full, stop irrigating until water soaks in, then turn the sprinklers back on.
Use underground sprinklers with flat-head sprayers; run them early in the day to keep leaves dry and prevent disease. Soaker hoses work well on flat ground.Trees
Non-native trees benefit from a monthly deep soaking. Put a rose-type sprinkler under the canopy (don't let the spray hit the trunk) and let it run until you've applied 2 inches; move the sprinkler to wet the entire root zone. Or use a hose-end, deep-root irrigator and insert it about 12 inches into the soil; run the water for 10 to 15 minutes. Depending on the size and age of the tree, repeat 3 to 11 times, moving in a circle under the dripline of the tree.
Most vegetables do best with roots kept moist and leaves kept dry. Young seedlings need water as often as two times per day for short periods; larger plants need more water to a greater depth. Group vegetable plants by growth rate and mature size, as well as by water needs. Use soaker hoses beside rows on flat ground. Or run a gentle stream of water from the hose into basins or furrows around plants.
Water only in early morning (when cool temperatures minimize evaporation), and avoid watering on windy days. Cover the soil under permanent plants with 2 inches of organic mulch such as compost or ground bark. The mulch holds in moisture and gradually decomposes and enriches your soil. Keep it away from the base of trunks. If you live in the Southwest or Northwest where summer rains are likely, use your roof to collect rainwater. Let gutters channel it into rain barrels or directly into landscape beds. For tips, how-to information, and sources, go to www.harvesth2o.com.