Thursday, April 24, 2014
 
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COLUMN

Freeze damage, fairy rings and millipedes

By John Fulton

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[April 24, 2014]  Freeze damage: I mentioned freeze damage in the column last week. Now that some time has passed, it is somewhat easier to assess damage  and take corrective action. Damage may still appear worse than it is today, but it won't improve any. The reason I say it may get worse is the simple fact that brown leaves on broadleaf evergreens are still attached to stems that have some life in them. If damage was severe enough, the stems will also continue to die back a little further.

Broadleaf evergreens  including boxwood, azalea, rhododendron, holly and yew  probably took the last cold snap the worst. The statement of fact is simple: Leaves that have turned brown will not turn back green. There may be live buds yet on some of those stems with some life in them, where the layer under the outside is still green and pliable. In some cases there isn't any hope for some of the branch tips, or even for some of the branches.

If there is still green under the dead area, you could always prune or shear just under the dead area. This would get rid of the dead material for the sake of appearance and also help spur new growth. An added benefit would be thickening the remaining shrub or tree. Entirely dead branches should be removed. After removing these, and giving the haircut, you can assess what is left. Then you can determine if you want to keep that  or start over. Pruning this early in the season may lead to some "rank" growth. This could be pruned again at the proper time in late June.

Fairy rings

Dark green grass in rings that look like a target pattern is a symptom of fairy rings. Fairy rings are visible now. Fairy rings are caused by a fungus that is in the soil. Actually there are about 50 fungi that can cause fairy rings. These fungi feed on decaying organic matter such as large roots from trees that were in the area or from buried lumber. The dark green circle part of the equation comes from extra nitrogen that becomes available as the organic matter is broken down by the fungus.

Some prevention will help keep the problem from occurring. Simply removing stumps and large roots and not burying lumber will help prevent this type of problem.

As for a cure, fungicide drenches have been successful on a very limited basis. One option is to mask the symptoms of the dark rings by fertilizing the surrounding grass with a high-nitrogen fertilizer to make that grass green also.

Millipedes

What are millipedes? They belong to the arthropod class Diplododa, which means double-footed. The reason is simple: They have two legs per body segment. There are many different types of millipedes  over 1,000 actually. They prefer to live in moist places, such as under mulch, in flower beds, in good-quality lawns and under wood. They feed on decaying organic matter and occasionally on tender leaves or roots.

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Unlike centipedes, millipedes don't bite or sting. They do give off a bad odor when disturbed or smashed. Be careful crushing them on carpeting, as they can cause a stain.

If you're not sure whether you have millipedes or centipedes, here are some differences: Centipedes have one leg per body segment, while millipedes have two; centipedes normally have much longer legs than millipedes; and centipedes move rapidly, while millipedes move slowly.

Nonchemical controls aim at removing the moist resting places. Dethatch your lawn to reduce that damp thatch layer just above the soil surface; closely mow and edge the lawn to allow it to dry quickly; remove debris that provides hiding places; pull mulch away from the house; water grass in the early morning; and keep leaves from piling up along the foundation.

If millipedes get inside the house, the vacuum cleaner is probably the best control. It is nonchemical and prevents stains from smashed millipedes. Other controls in the home include sticky boards such as are used for mouse control, aerosol sprays that are used for flying insects, and baseboard sprays used for ants.

Outside the house, start with a foundation spray such as propoxur, permethrin or Sevin. Spray the foundation and the adjacent foot or so of soil and plants or lawn. Make sure you treat doorways and other openings as well. Since millipedes aren't insects to begin with, don't expect complete control with a chemical spray program.

[By JOHN FULTON, University of Illinois Extension director for Logan, Menard and Sangamon counties]

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