Desiccation    

By John Fulton

[April 16, 2007] While the damage from the freezing temperatures is evident, maybe just as bad was the wind. Wind dries things out, especially at lower temperatures. Colder air just can't hold as much moisture as warmer air, and the combination of cold and windy is just a double whammy.  [Star of Bethlehem pictured at left]

Some plants show the damage from drying winds more noticeably than others. White pines are almost the kings when it comes to visible damage. The damage shows as brown needles. When you look at damaged evergreens, the key thing is the bud. If buds are still plump and green, new growth can occur, even if all the needles are brown. Also, with evergreens, remember that they only keep up to four years of growth. The older growth toward the center trunk falls off each year, usually in a gradual process so it is hardly noticed. In a stress situation, such as drought or temperature extremes, many needles suddenly turn color and drop. This is quite noticeable, but the results are the same as the usual gradual loss of needles.

Evergreens and tender, succulent plants are most susceptible at this time of year. Hopefully nobody got caught with the latter out at this time of year, so that left evergreens. It is even more noticeable since the foliage doesn't drop off every year. But, it does drop off. That's why you get inches of needles that build up under a mature tree.

What can we do? At this time it's like "take two aspirin and go to bed." In the case of trees and shrubs, this means to water when it is dry and fertilize with the normal lawn rate in May and September. If you are fertilizing the lawn, you have taken care of the trees and shrubs.

There would have been some preventive things that could have been done. One option is to block some of the wind with a screen of some sort. A second would have been to spray foliage with an anti-transpirant to slow the moisture loss from the needles.

With plump, green buds there should be new growth occurring shortly.

Star of Bethlehem
(pictured above at left)

One of the more prevalent "different" weeds this year has been star of Bethlehem. This is a weed that looks like wild onion or garlic but doesn't have the odor. It can also have a small white flower. It grows from small bulbs, so tilling an infested area is not a good idea.

Control is difficult. Traditional lawn weed herbicides don't touch it. Recommendations have been repeated Roundup use or use of Gramoxone (paraquat). Of course, both of these also kill most anything they come in contact with.

Some research out of Virginia shows some promise for carfentazone ethyl, which is usually mixed with traditional broadleaf weed killers such as 2,4-D or dicamba. Gordon Chemical has the sole lawn product and sells it as SpeedZone. I don't know of any distributors around here, but you may find it out of the area. This product could be used on lawns without affecting the grass.

Periodical cicadas

2007 is the year for the periodical cicada northern Brood VIII (17-year cicada) to return. The southern boundary of their range is from Iroquois County to the northern edge of Sangamon County to the Quad Cities. That puts Logan County at least partially in the range; however, 1990 saw little activity in our area.

In heavily infested areas, new plantings of trees with small diameter are discouraged. Larger trees look rough for a year but are largely unaffected. I'll have more on cicadas in a few weeks, as their emergence is generally toward the end of May.

[Text from file received from John Fulton, University of Illinois Extension, Logan County Unit]