PRAIRIE GARDENER: Ash borer leaves thousands of dead trees in its wake

CLEVELAND -- There is both good and bad news on the emerald ash borer scene this week. Let's begin with the bad news. On a mid-autumn motor coach tour, sponsored the Grand Forks Senior Citizens center, the Prairie Gardener and others enjoyed a pr...

CLEVELAND -- There is both good and bad news on the emerald ash borer scene this week. Let's begin with the bad news. On a mid-autumn motor coach tour, sponsored the Grand Forks Senior Citizens center, the Prairie Gardener and others enjoyed a preview of fall colors all the way from the Berkshires of eastern New York state to the scattered forests of Pennsylvania.

But in Ohio, grim reminders of the emerald ash borer emerged as the Prairie Gardener noticed numerous dead trees not only on farmsteads, but in windbreaks and even forested areas. The borers attack green, white and black ash species. More than 900 ash trees have been cut down as of July to prevent the spread of the emerald ash borer. The situation in that lake-front city appears to be dire.

Ohio forestry officials report there is little hope left for the state's ash trees. The insects have been discovered in the Wayne National Forest in the southeastern corner of the state, which have lead officials to decree that the borer is now in all of Ohio's 88 counties.

As a result, Ohio has revised its quarantine of ash tree materials and firewood. The new quarantine prevents people from transporting ash tree materials and firewood out of the state. But now residents can transport the wood throughout Ohio if they use caution. Residents are strongly encouraged to buy their firewood locally.

The ash borer was first identified in Ohio in 2003, according to the state's Department of Agriculture. About 10 percent of the Ohio tree population is ash, so the state has much to lose. The borers, which are a native of China, kill ash trees by boring under the bark to lay eggs. The tunnels disrupt the flow of water up the trunk so the trees are slowly strangled. It takes three to five years to kill the tree.


The national forest spans 12 counties and covers 240,000 acres. Traditionally, ash trees are cut down to prevent the spread of the bug, but the national forest will let its 20,000 or so ash trees stand in hopes of finding one that may be resistant to the borer. Officials are unsure of the ecological impact of the tree species' death. But non-native pests have attacked other trees one by one, and over time could have a large impact on forests.

Houston County, Minn.

While the situation looks bleak in Ohio, there may be some better news from Houston County, the most southeasterly county in Minnesota. Here researchers have released thousands of stingless wasps on a Mississippi River island recently, looking for a way to slow the borer's progress before it devours the estimated 957 million ash trees in Minnesota.

The wasps, brought over from Asia, look like fruit flies, but don't harm humans. They are parasites, using ash borer larvae as a host for laying eggs. The five-year study is the first of its kind in Minnesota, but similar experiments have been conducted in Michigan, Ohio and Indiana. Researchers here will measure the effect on 12 trees in the Upper Mississippi River National Wildlife and Fish Refuge. The wasps should control the ash borer population without eradicating it.

Houston County and three neighboring counties in southern Wisconsin and northeastern Iowa are under quarantine because of the ash borer infestation. Ash borers have also been found in the Twin Cities area. So far, there have been two positive finds, which researchers claim to be good news. Let's keep our fingers crossed.

Forestry officials have given no timetable when the ash borer will be in our backyard, but it may take some time unless the borers are carried in with firewood to this region. Once established, homeowners can combat the pests with spray or simply cut down ash trees and start over again. Neither is a good option.

Geranium tips

With colder temperatures now moving it, many gardeners want to save some of those beautiful geraniums and other outdoor flowers from Jack Frost. For the occasional frosty night, an old coat or bed spread will take care of the problem. Don't use plastic sheeting unless in case of an emergency. Any foliage that touches the plastic will freeze so try to keep plastic above the plants.


One easy way to over-winter geraniums is to simply take cuttings of your favorites. The so-called slips should be 4 inches long and of the new green wood, not old woody stalks. Some gardeners leave the slips overnight so the cut ends will slightly dry. Dip the ends in rooting hormone powder and stick 2 inches deep in the potting material. Give limited sunlight. It takes three to four weeks for the slips to develop roots.

You also can pot plants and bring them indoors for winter. Cut the plant to about one-third of its original height. Carefully dig and place in a 6-inch or larger pot. Water well and place in a sunny window. The cut ends can be treated as slips, too.

The old-fashioned method of carrying over geraniums is to dig the plants, shake well to remove excess soil and hang them over the basement stringers. This works best in a root cellar, not heated basements. The Prairie Gardener dries off the plants for several days before placing in brown grocery bags. This prevents mold.

If you have a plant you really like, take slips in case you lose the plant. During winter, sprinkle now and then with warm water. There should be a bit of green stalk or small leaves when you take them out in spring. You can either refresh them in early spring sampling by replanting and placing in a sunny window so they will develop by spring, or you can plant them directly into the garden after frost danger. It's best to soak the roots in warm water for a day or two, so they will fresh up. Keep them watered once they are out in the garden.

Canning big

The renewed interest in home vegetable growing the past two years has also sparked similar interest in home canning. Once dismissed as a tradition of a bygone era, canning is making a comeback. A National Gardening Association survey showed 28 percent of the households that participated in food gardening also preserved food in 2009. Sales of food preservation items at Jarden Home Brands, which makes Ball and Kerr brands, have jumped 60 percent from 2007 and have risen about 10 percent this year. Unlike the early 1970s, when there was a similar burst of interest in vegetable growing and home canning, lids are still in abundance. Three decades ago, we were forced to hoard our precious lids and searched everywhere to keep up our supply before the crisis ended. Only purchase enough for current use, don't hoard.

Koehler is the Herald's garden columnist. Send garden questions to him in care of the Grand Forks Herald, Box 6008, Grand Forks ND 58206-6008.

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