It's that time of year again: 90-degree-plus temperatures, accompanied by the snap, crackle, and pop of grass under your feet. Strolling through Conservation World last Sunday at the Illinois State Fair, my family complained of thirst. How did the plants feel?
A thirsty plant will wilt, and then lose its leaves. Most plants benefit from one-inch of water per week, but many gardeners use more to encourage growth. With this summer's rainfall, few will remember that just several short years ago Springfield was facing a drought and we could water our lawns only on certain days of the week. When times are good, it's easy to forget about conserving water.
Just 1 percent of the world's water supply is available for drinking. But conserving water not only saves a precious natural resource, it reduces the cost of water bills and protects our water quality.
During the summer, lawns and plants can account for half of a typical household's water consumption. So conserving water should start with a landscaping plan. How much sunlight does your yard get? What's the condition of the soil? How's the drainage? Select plants that are suitable for the site--native plant species have low water needs. Group plants according to their water needs. Prior to planting, work the soil deep and, if needed, add amendments, such as composted yard waste. Well-drained, loose soil will allow roots to go deep to better obtain water and nutrients.
Here are some more tips for reducing your water consumption:
• Water early in the morning, before 8 a.m., or in the evening, after 6 p.m.
• Avoid watering on windy days.
• Most plants, including your lawn, prefer one-inch of water per week. Depending on the soil type, one-inch of water will wet the top six to eight inches of soil. You can use an inexpensive rain gauge to check soil moisture.
• A slow, thorough watering is better than several light sprinklings. Deep watering encourages root growth, which helps plants survive drier conditions. Soaker hoses and drip-irrigation systems are generally more efficient and cause fewer disease problems than sprinklers. Hand watering generally doesn't penetrate the second inch of soil--thus you waste water and time.
• Watering newly planted trees and shrubs should be your top priority. Don't just water at the trunk--soak the entire area beneath the tree canopy because that's where the roots are growing.
• Cool season turfgrasses, such as Kentucky bluegrass, can survive extended periods of drought by going dormant. Leaves will become brown, but roots and crowns remain alive for four to six weeks. Don't start watering your lawn until the first sign of stress: when footprints remain in the turf. Once you begin to water your lawn, you must continue to do so.
• Mow higher, avoid traffic, and don't use pesticide on drought-stressed lawns. Do not remove more than a third of the leaf's blade when mowing. In the hottest, driest weeks, that means letting your grass get three-and-a-half-inches tall before you mow.
• Ground covers require less water than turfgrass. Consider replacing some of your lawn with ground cover.
• Use organic mulches around your plants. Shredded hardwood bark, wood chips, and composted shredded leaves will conserve the soil's moisture, improve its structure, and moderate its temperature. Mulches should be two- to four-inches deep and kept away from plant stems.
• Reduce competition and stress by keeping weeds, insects, and diseases under control. Stress and competition increase the water demands of a plant.
For more tips on reducing water usage inside and outside the home, visit the American Water Works Association at http://www.awwa.org.
Time to divide Irises
Bearded irises are among the easiest perennials to grow. Late July to early September is the best time to plant or divide an iris, which needs to be divided every three to five years. The iris loves heat and dry weather, and summer dividing will reduce bacterial soft rot.
When dividing an iris, cut back foliage to one-third of its height, then lift the entire clump with a spade or digging fork, leaving the roots attached. With a sharp knife, separate the rhizomes (the creeping stems lying at or under the surface of the soil, producing roots from its undersurface). Each new transplant should have a firm rhizome with roots and a fan of leaves. Discard old rhizomes and any rhizomes with rot (soft and mushy) or iris borers (pink caterpillars inside the rhizome).
Plant the iris in a sunny and well-drained area with soil cultivated eight inches deep. Plan to space rhizomes 18 inches apart. For each rhizome, dig a hole about 5 inches deep and wide enough to accommodate the rhizome and its roots. Build a small mound of soil in the bottom of the hole and firmly place the rhizome on it. The leaf fans should face one direction. Spread the roots out, and cover them with soil till the rhizome is just slightly exposed (rhizomes planted too deep will rot). Water well after planting; unless there are drought conditions, no further watering will be needed. An iris is one plant that never needs mulch.