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.
This article appears in Aug 21-27, 2003.
