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October Lawn & Landscape Tips
featuring tips on protecting evergreens from winter injury and fall weed control
by Don Janssen, UNL Extension Educator
Winter Injury to Evergreens
Landscape evergreens will soon face another moisture-related crisis: winter. Evergreens exposed to bright winter sunlight may lose moisture through their leaves all winter. As the sun heats the foliage, vapor pressure builds up inside the leaves or needles and moisture escapes into the dry air around the foliage.
The problem is that the roots, encased in frozen soil, can not readily replace the moisture that is lost. The result is often browning of foliage and loss of parts or all of affected plants.
Broadleafed evergreens such as rhododendron, boxwood and evergreen euonymus tend to suffer most severely, though some taxus (yew) cultivars and junipers may also be damaged.
The first step in preventing this damage is to water plants in the fall so they go into winter with a good supply of water for the roots to take up as long as they're able. If fall rains don't supply about an inch of water per week, water thoroughly and deeply every 7 to 10 days until the ground freezes.
The second step is to shade plants from the sun. Canvas or burlap tacked to stakes placed on the south and west sides of plants will keep direct sun off the foliage and so help reduce moisture loss.
You can minimize the need for this shielding by planting susceptible plants in naturally sheltered spots, such as on the north side of a building, hedge, fence or other structure. Such plants won't need special shielding but may still need watering in the fall to help them get through the winter in good shape.
Fall Weed Control
Plants that never seem to be bothered by drought or winter are weeds. So how do you control them? By timing their control measures when they are most vulnerable, in the fall.
Many homeowners remain hard to convince that fall is an ideal time to treat lawns for not only dandelions, but other troublesome weeds.
All the factors are present for an effective lawn weed control program, only the homeowners's resolve is needed.
Broadleaf turf weeds that make fall growth -- including dandelions, field bindweed, chickweed, shepardspurse, henbit, ground ivy and violets -- can be controlled most effectively anytime in October or early November.
Fall treatment of turf weeds has these advantages:
-- Weed elimination permits turf grasses to fill in areas occupied by weeds.
-- Late fall applications come at a time when gardens, most ornamentals and trees are less subject to herbicide injury.
-- While some weeds are not killed with herbicides, fall treatments cause them to go into the winter in a weakened condition, making them more susceptible to winterkill.
Weeds not killed by spring treatments, on the other hand, go into a period of favorable plant growth and are likely to recover.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office
Contact Information University of Nebraska-Lincoln in Lancaster County
Web site: lancaster.unl.edu
444 Cherrycreek Road, Suite A, Lincoln, NE 68528 | 402-441-7180