Lake Region State College is planning a series of seminars focusing on Introductory Precision Agriculture with the first seminar beginning on January 15th. Each seminar will consist of five classes which will meet on Monday and Wednesday afternoons from 1-4 PM at the Dakota Precision Ag Center (DPAC) located 1.5 miles north of the main campus (5070 Hwy 20 N) on North Dakota State Highway 20.
The first class in the Introductory seminar will focus on DC Electronics specifically in troubleshooting. The Introductory 5 class seminar will also be repeated beginning on February 5th. A more advanced seminar will begin February 26th.
Enrollment will be limited so those interested in participating are encouraged to contact Lisa Howard, DPAC Program Coordinator, at 701-662-1498 to reserve a spot. The class is worth one credit and will cost approximately $155 for students in the Lake Region State College Farm Management Program; if not a prior LRSC student a $35 application fee will be added.
Causes of Winter Injury to Landscape Plants
Most landscape plants grown in North Dakota are hardy enough to withstand all but the lowest temperatures. Winter death to what are considered hardy landscape plants basically has two causes:
Desiccation This frequently happens to evergreens when the sunlight intensity is high, causing the plant tissue to become physiologically active. Water is lost at this time and cannot be replaced because the soil water is frozen.
Freeze-thaw cycles These are common on herbaceous plantings that were not given mulch protection before winter. Freeze-thaw cycles occur during our typical February/March thaws and refreezes. The crown of the plant is heaved, causing roots to be exposed to air temperature fluctuations. The root system has a lower tolerance to temperature extremes and may be killed by a lethal low temperature.
Other causes for physical damage to woody plants are wet, heavy snows, or freezing rains and sleet. Expect this to show up on soft-wooded trees such as silver maples. The weight borne by the branches causes rip and tear breaks. The best action is to clean up broken branches immediately by cutting them back to a crotch or healthy branch.
To minimize winter desiccation, plant sensitive species in sheltered locations, provide companion plantings that are more resistant to winter desiccation, or screen plantings with burlap, evergreen boughs or discarded Christmas trees. All of these measures will slow the loss of water from the valued plant material.
Commercially available anti-desiccants can be sprayed on the plant foliage in late fall and again in late winter to provide some protection. The clear, protective film slows water loss from plant tissue exposed to the elements. Be sure to check the label for sensitive plants.
Another problem faced by thin-barked trees is sunscald. Sunscald is a winter time injury to tree trunks, caused by the sun. Deciduous trees are without leaves, night temperatures often fall below freezing, and the winter sun is low in the sky during the winter months. These factors combine to cause sunscald.
Here's how it happens: Assume a young, thin-barked tree is warmed on a sunny day in January. The sun is at a low-angle and it warms the south and southwest sides of the trunk, causing inactive, cold-hardy bark cells to "think spring." Then the sun sets and the temperature drops below freezing, killing the bark cells.
Young, thin-barked trees are most at risk for sunscald. These include willow, mountain ash, fruit trees, maples, and ashes.
Wrapping thin-barked young trees with paper, burlap, or PVC tubing before the onset of winter, then removing the wrapping the following spring once the frost is out of the soil can help prevent sunscald.
Checking the herbaceous plantings as winter grinds to a close to see if resetting or remulching is needed will cut down on loss. Covering the plants prone to heaving (mostly new transplants) with a light organic mulch once the soil has frozen initially will help minimize this type of loss.