NDSU Extension - Williams County


| Share

2015 Wheat Show Planned - Sunburn trees in the Winter - Lawn Aeration

Published September 28, 2014
2015 Wheat Show Planned - Sunburn trees in the Winter - Lawn Aeration

Wheat field

2015 Wheat Show Planned

Plans for the 62nd Annual National Hard Spring Wheat Show are nearly complete.  The dates are February 2nd, 3rd and 4th with the site being the Grand Williston Hotel.  As in the past, almost 20 speakers are scheduled to present new information that can be applied to profitable food production.  One of the keynote speakers will be Dr. Mike Boehlje, Distinguished Professor of Agriculture Economics and the Center for Food and Agricultural Business at Purdue University.  Dr. Boehlje is involved in teaching, research and executive education in agriculture finance, farm and business strategy and management and structural change in the agricultural industries.  The major theme of his work is the importance of strategic planning and thinking, and positioning the firm for long-term success in a turbulent business climate.  During his three hour presentation, Dr. Boehlje will discuss many issues which farm producers can use for future planning including a predicted cyclical downturn in agriculture.  More information about the total education program and other activities will appear in my future columns.

Sunburn in the Winter

Yes, this can happen to trees, especially the young and those with smooth bark.  Here is how it happens.  Remember, a tree trunk receives no shade in the winter.  Its branches are leafless and the trunk is exposed.  On a sunny afternoon, the sun casts its rays upon the trunk and heats it up.  Temperatures on the sunny southwest side of the tree can be as much as 77° warmer than on the north side.  This heat causes the dormant cells beneath the bark to become active.  When the sun sets, the trunk rapidly cools.  The activated cells freeze and burst, causing the bark to crack.  Maples are a good example for possible sunscald.  Others are linden, mountain ash, honeylocust, plum, cherry, crabapple and apple.  Just look on the southwest side of these trees for vertical cracks which are a good sign of sunscald.  Wrapping the above sensitive trees for at least their first two winters will be very helpful in preventing sunscald.  In fact, if you have a great love for the tree, I would wrap them for their first five winters or until the bark develops texture.  The recommendation is to use kraft paper, starting at the base and winding the paper up to the first major branch.  Another possibility is to place white plastic tree guards around the trunk.  This protection will reflect the rays of the sun off the trunk, keeping it cool.  Unwrap the tree after the last frost in the spring to let the trunk expand and prevent insect infestation.  There is a word of caution when choosing a tree wrap.  Do not use black tree guards.  This absorbs heat, which is the last thing you want to do.


Over the years I have received many questions about aerating lawns, mostly about when.  Tom Kalb, NDSU Extension Horticulturist, suggests “now” as the best time of year.  This aeration will promote a stronger root system and reduce thatch problems.  Kalb suggests using self-propelled core aerators and making two to four passes.  He avoids drum rollers and solid tines.  These may actually compact the soil.  Kalb believes there is some benefit to aeration but firmly believes most lawns will never need it.  I must agree.  If a lawn is properly managed with adequate watering and fertilizer, and is growing on well drained loamy or sandy soil, aeration is just a replacement for good physical exercise.  If your lawn soil is largely of clay aggregates and compacted, then aeration has some benefit.  Spring is also a good time to aerate lawn but aeration in the spring may promote weed growth because of the soil disturbance.

-Warren Froelich

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.