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SORRY, TOM; DEER TICKS; EVERGREEN WINTERKILL
I stand corrected. Last week I said Purple Wave petunia has been a hard plant to find at garden centers. Tom Hayden, owner of Chaska Farm & Garden, informed me over the weekend that he has had Purple Wave on hand every year, so my new advice is to stop in at Tom's store and give this All-America winner a try.
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I found a deer tick crawling around on my neck this week. Since moving from Minneapolis three years ago, I've picked hundreds of wood ticks off my body, and thousands off Spud (my dog), but this is the first deer tick I've encountered. At least now I'll have an excuse next time I feel achy all over!
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Many people have called in recent weeks lamenting their dead-looking evergreens. Hardest hit seem to be yews and arborvitae, but spruce and pine also suffered significant winterkill.
Browning or bleaching of evergreen foliage occurs for three reasons:
1. Winter sun and wind cause excessive transpiration (foliage water loss) while the roots in frozen soil are unable to replace lost water. This results in desiccation and browning of the plant tissue.
2. Bright sunny days during the winter warm tissue above ambient temperature that stimulates cellular activity. Then, at sunset, the foliage temperature drops to injurious levels (up to 17 degrees per minute!) and the tree is injured or killed.
3. During bright, cold winter days, chlorophyll in the foliage is destroyed (photo oxidized) and is not re-synthesized if the temperature is below 28 degrees. This results in bleaching of the foliage.
Winter browning occurs most often on the south, southwest and windward sides of the plant and, in severe cases, the whole plant may be affected.
If your evergreens suffered winter injury, there is no magic potion that will turn them green again. Best option is to prune out the injured foliage. The brown foliage is most likely dead and will not green up, but the buds, which are more cold hardy than the foliage, will often grow and fill in the area where the brown foliage was removed. If buds do not emerge, prune off the dead branches. Fertilize winter-injured plants now and water them weekly throughout the growing season (except during periods of excessive rainfall).
That's the bad news. The good news is that you can help evergreens prepare for next winter's severe conditions. The first way is to only plant evergreens bred for Zone 3 and 4 climates (Chaska is in Zone 4). Ask the retailer about the source of all plant material and don't plant anything that wasn't propagated in the north. Most reputable garden centers will tell you the origin of their plants.
Second, select a site that protects the evergreen from winter stress. Don't plant yew, arborvitae or hemlock on the south or southwest sides of buildings or in extremely windy or sunny areas.
Another technique is to protect evergreens from winter wind and sun by constructing a burlap barrier on the south and west sides. Or, you can stack pine boughs or some other homemade barrier to catch more snow for natural protection.
One person I talked to last week sounded borderline suicidal about her brown arborvitae. I asked her how long her arborvitae plants had been growing next to her house and she said about 18 years. I told her the best solution would be to cut them down and plant something new and fresh. Too often we think trees and shrubs should live forever. The fact is, there is always something new and exciting that we can select to replace a plant that has outlived its usefulness.
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PUTTING DOWN ROOTS:
A Delightful Blend of
Gardening Wisdom, Wit
and Whimsy
$10 + $2 for shipping
by Cliff Johnson |
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