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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

Shearing helps produce a uniform shape and a more marketable tree. © Robert Queen

December 1997

That perfect tree

Christmas trees can be grown "greener" if the buying public will accept them or seek them out.

Katherine Esposito



Shearing helps produce a uniform shape and a more marketable tree.

© Robert Queen
Weaning from pesticides | Changing attitudes and markets
Stay in touch with trees | Growing and marketing green trees

On a cloudy summer day in a sandy 40-acre field covered with thousands of closely manicured Christmas trees, an emerald-green frog the size of a quarter jumped off a stalk of tall grass. Within seconds the creature leapt again, determined to avoid the fingers of a curious visitor. It succeeded.

To Ken Appel, a hard-charging field supervisor for the Wautoma-based Campbell Tree and Land Co., the tiny frog was a distraction. Appel was busy seeking dried rivulets of pine pitch, the telltale sign of a well-fed Zimmerman pine moth, on the trunk and branches of a Scotch pine. It didn't take too long to find some.

He grabbed a branch from a different tree. Yellowed needles began to fall, not unlike the way they do after a Christmas tree has been in a heated home for a month and slowly begins to die. Appel's tree, with roots still firm in the ground, was dying, too. But not in the manner he had planned.

What had been a great summer for tree growth, with nary a week without rain, proved to be a banner year for pests as well, especially in the giant Scotch and white pine plantations in the Central Sands region, home to the state's largest concentration of Christmas trees. Many of the Campbell's fields were plagued by the Zimmerman pine moth. Not far away, fields belonging to the Kirk Company were menaced by spittlebugs. Both growers, two of the country's largest providers of holiday trees, expect some losses.

The entire 90 acres of infested Campbell land was soaked in early spring with the insecticide dimethoate, applied by a machine capable of blasting ten rows at a time with powerful horizontal sprayers. Apparently, the chemicals didn't work. So in fall the company harvested as many uninfested trees as it could for sale to retailers, and this month will chop down the rest. Next year, a different chemical will probably be tried on fields with smaller infestations.

Farther north, in Price County near Timm's Hill, the highest spot in Wisconsin, the same wet weather meddled with Don Carney's hopes for his Christmas tree harvest. His problems were of a different sort: a few of his 15 acres of balsams had been badly scourged by balsam twig aphids, and he faced the likely loss of a quarter of his planting. Carney had noticed the pest in 1996, but had chosen an alternative to synthetic insecticides, a homemade brew of tobacco tea, Listerine, and dish soap, sprayed on individual trees several times over the summer. It had worked well enough that year, but when the bugs were encouraged by rainy skies in 1997, Carney gave up. He and his son, Jim, strapped on backpack sprayers and walloped the bugs with diazinon.

It was a disappointing moment for the retired National Park Service naturalist and historian, who celebrates the return of eagles, fishers and frogs to this land where he was raised.

"I've never seen so many frogs as this year," Carney says.

"None of us like that chemical business," he continues, referring to his wife and Jim, who work alongside managing their 6,000 trees. He doesn't call himself a strict environmentalist – "I'm not a believer in global warming," he comments, but he has read stories of deformed frogs in the newspapers, and he worries that using strong chemicals on his land will harm frogs, other wildlife, and reduce the good insects that eat the tree pests.

"If you use diazinon or other toxic pesticides, there's always a chance it will get into the food chain, and kill birds and other beneficial insects," he says.

Weaning from pesticides

Carney's attempt at alternative pest control is not common. But there is a tiny trend among tree farmers, encouraged both by basic economics and a dollop of environmental fervor, in favor of reducing chemical use. Moneywise, after all the debits and credits are tallied – labor, chemicals, equipment costs and depreciation, plus the return on trees sold – farmers are thinking it doesn't make sense to try to kill every insect and cure every disease on every tree. Some trees will recover on their own, perhaps helped along by predatory birds and bugs. Some won't, and the grower may calculate if the few dollars forfeited from those trees is less than the cost of attempted cures. Some branch and needle damage may simply not be severe enough for shoppers to notice.

Unfortunately, once insecticides are applied, farmers can't stop using them. The unwanted bugs may disappear for a season, but treatment also destroys desirable insects that would feed on them or the next pest waiting to swoop down. And it can take three years of totally pesticide-free farming before those good insects return. Many farmers find it difficult to ignore pests feasting on even a small patch of trees.

Pesticides are only short-term solutions to insect infestations. © Robert Queen
Pesticides are only short-term solutions to insect infestations.

© Robert Queen

Bill Kearby, a retired DNR entomologist with a 70-acre tree farm near Sheldon, spent his career advising farmers of the proper time to spray for a particular insect. But when it comes to his own trees, Kearby just watches and waits.

"Nature seems to be very effective," Kearby says, as he described his own skirmishes with the balsam gall midge, balsam twig aphid, and white pine blister rust, a fungal disease. His techniques are simple: limited weed mowing, to give ladybugs, parasitic wasps, flower flies, and green lacewings some hiding places, and no insecticides. Any outbreaks have almost always cleared up by the next year, he says, and when they haven't, Kearby has cut down the infected trees and burned them. Lesser damage can usually be sheared off, he adds. "So many people today want to produce a perfect product. That's sort of ridiculous, I think."

Across the state, every method imaginable of growing Christmas trees can be found. Some growers are huge, with hundreds of thousands of trees sold throughout the country. Some are tiny, like Don Carney, with perhaps a few hundred harvested each year. But for 20 years now, all of them have been hearing the same message, often given the moniker "IPM," for Integrated Pest Management: that monitoring fields for pests and diseases, and paying more attention to a tree's culture, is economically and environmentally smarter than wholesale preventative chemical spraying. And while most growers don't have quite the love affair Carney has with his trees, most agree their attitudes have changed over that time period.

Changing attitudes, changing markets

Gary Nelson has grown trees on the Kirk Co.'s 7,000 acres for 19 years, the last six as district manager. In the 1970s and before, he says, no one waited until a problem was detected before aiming a fusillade of chemicals at a field. "Preventative spraying was done, routinely," he says. "It's easy to go out and throw a bunch of spray on."

Peter Grimm, Campbell Co. general manager, with 20 years experience working the firm's 5,500 acres, agreed with Nelson. "The theory before was that everyone went ahead and sprayed, regardless of whether there was a problem or not," he says. And for a while, it probably made sense with Scotch pines, for many years the pearl of Christmas trees.

Those pines, which accounted for 60 percent of the holiday tree market only about six to eight years ago, are down to about 29 percent today. They grow like Topsy in the sandiest soils without ever crying out for fertilizer.

Unfortunately, they are also especially buggy and disease-prone: a December 1995 pesticide manual jointly produced by Michigan State University Extension and Wisconsin DNR lists 20 insects and six diseases known to afflict Scotch pines, compared with nine insects and one disease for balsam firs. But as long as they were the hottest trees around, and before groundwater protection became a big issue, the extra expense of controlling all those problems didn't much matter.

It finally began to matter around the late 1980s, after hundreds of people who had planted Scotch pines, hoping to cash in on the trend, began to offer them for sale. Around the same time, holiday buyers simultaneously started to prefer balsams and their Southern cousin, the fragrant Fraser fir, and a glut of Scotch pines was the result.

Today, fields containing more dead pines than live ones are evident in Waushara County and places nearby, left to fend for themselves by independent farmers who couldn't get a good enough price for them, and who couldn't afford to maintain them either. Now, the dying stands frequently host a variety of bugs and diseases, which can concern other growers with healthier fields nearby. As he motors along 20th Drive in Wautoma, Ken Appel spies one such stand. He points to trees left unshorn, weeds chest high, yellowed needles from the Zimmerman moth and trees rusty from bottom to top, dead from another common pine cancer, the root collar weevil.

"That field is saying, 'Help me,'" Appel says. "There's so many insects in there – that's where they thrive. Somebody thought they would make money in trees – that God takes care of them." But God doesn't, as successful farmers have realized. Even growers blessed with healthy trees tell stories of long hours spent in their fields, observing, mowing, culling, and, more or less, spraying.

Though Grimm and Nelson cut their teeth on older methods of controlling pests, they have adapted somewhat to the new tenets of IPM. The two men and their dozens of employees spend more time in the fields now, trying to avoid any noxious surprises.

Using IPM sometimes results in a more measured response than in years past, as in 1996, when Grimm decided not to go after a mild infestation of spittlebugs with the insecticide diazinon. Last June, however, Grimm went ahead and sprayed. "Sometimes you can live with damage, until it gets to the point where, economically, it's not feasible," he says.

Grimm isn't sure that his company has actually managed to reduce their use of chemicals, however. And Appel says he doesn't hesitate in the slightest to protect his trees in any way necessary. State entomologists may recommend waiting to see how bad an infestation gets before spraying, "but when I see a disease, I go ahead and use [chemicals], and not wait," he says.

Of course, there are several clear reasons why some pine species in the Central Sands region have developed so many problems, factors Nelson and Grimm appreciate. Many varieties of Christmas trees are considered exotic, hailing originally from Europe, but the natural ways to control pests and diseases weren't imported with them. They have been grown on the poorest soils, on which farmers couldn't beg anything but a Scotch to grow. They never are fertilized, which doesn't curtail their height but might deprive them of health-affirming nutrients. And they are usually grown in huge tracts of 50,000 trees or more.

That practice, commonly called monoculture, is known for resulting in serious pest and disease outbreaks in all kinds of crops. In an effort to break the infestation cycle, Nelson has planted corn on newly clear-cut tree fields, and believes it has helped. Farther south, in Waunakee, Joe CaPaul and his son, Joe, Jr., are deliberately avoiding the monoculture trap on their 35-acre choose & cut tree farm on River Road. On their site, shoppers can saw down a fresh tree and pet a couple of reindeer afterwards. It's easier, of course, when you don't fancy yourself getting to be as big as the Kirk or Campbell operations. Joe, Sr., now relies on a state pension as a retired University of Wisconsin-Extension computer manager, while Joe, Jr., is a DeForest High teacher. When you're small, you can pay more attention to the details.

One of those details includes the farm layout. At CaPaul's different species, including balsam and Fraser firs, Scotch and white pines, and blue spruce, are planted every five or 10 rows. That keeps insects that prefer one kind of tree from infesting more than a small number. Another detail is constant monitoring for new outbreaks and trying to time any pesticide applications to a very few days, when the bugs are most vulnerable. And when he and his son do spray, they use a backpack sprayer and cover each tree individually, a practice they also employ when killing weeds.

"I don't want to put down more spray than I have to. It really matters," says Joe, Sr. "If I started out spraying hard, I'd lose my angle worms." Garden worms, a mark of good, porous soil, were impossible for the elder CaPaul to find when he bought the property in 1960 and began growing Christmas trees instead of corn on most of the acreage. Now, after reducing chemical use and limiting the weighty tread of heavy machinery, CaPaul finds the worms returning and the soil improving. And better dirt makes for healthier trees, he believes.

Stay in touch with the trees

The Christmas tree farmers who can innovate most in defending against common scourges are those who live near their plantations, and have the time and interest to constantly putter in their fields, says Andrea Diss, a DNR entomologist based in Green Bay.

"Monitoring is more than half the battle," Diss says. "You've got to be around and observing trees regularly, so you catch problems when they're small. If you're living next to your plot, you're going to be more attentive. If your business is nothing but growing Christmas trees, you're going to be out there every day."

By keeping a close watch on tree development, growers can catch problems early. © Robert Queen
By keeping a close watch on tree development, growers can catch problems early.

© Robert Queen

And there are quite a number of tree farmers like that in Wisconsin. It turns out that three-quarters of the 400 members in the Wisconsin Christmas Tree Producers Association cultivate fewer than 250 acres of trees. They yearly harvest about half the state's three million Christmas trees, most of which are shipped out of state. Only five percent of the association's members till over 500 acres.

Many of those farmers are retired, or partly so. Some thought that growing Christmas trees might be an undemanding way to make some extra money ("Boy, was I mistaken," says Joe CaPaul, Sr. "This is the most labor intensive job I've ever done.") and some did abandon their efforts, occasionally leaving fields of Scotch pine to grow sicker and sicker. Others let their white pine and spruce grow up, ostensibly for timber harvest.

Not all principles of IPM work for every farmer, however. It depends on circumstances unique to each situation: the age of trees and size of the farm, soil types, the weather, land contours, proximity to other tree stands, the grower's gardening style, and just how many bugs or diseased needles he or she can bear. Both the CaPauls and Norma Swan, a spry 72-year-old widow who continues her late husband's balsam tree habit on 200 acres in Ogema, in Price County, had limited success with using imported ladybugs to gobble up the balsam twig aphid, though Bill Kearby swears by them. The aphids feed on new growth, and the tree's needles end up gnarled as a result. "Some years it can be real bad," Kearby says.

Kearby just lets naturally occurring ladybugs munch away, shears off any twisted needles in July and sells his trees as they are, shipping them to Minneapolis and other cities. He's never heard any complaints from customers about the damage. "They're not looking for that. They're looking for a nice, full tree, with good color," he says.

Swan and her husband Dave used to regularly import ladybugs from the East Coast for aphid control. They resorted to a round of diazinon one year when the ladybug shipment was delayed. "It just broke my husband's heart," she says. He was committed to natural methods of pest control. "When you spray diazinon, you kill the ladybugs, too. That's what's so disheartening," she says. "Aphids curl the needles and make the trees unsalable. I just don't know the answer to the problem." Swan has practically abandoned the use of ladybugs as a dependable aphid check.

Down in Waunakee, Joe CaPaul, Sr., has found getting the ladybugs to the aphids on exactly the right day just as troubling. "The problem is, you can purchase them, but if the aphids aren't there when you turn them out, they [the ladybugs] leave. That is a problem," he says. CaPaul uses malathion to kill the aphids.

Growing and marketing green trees takes time and commitment

Neither grower may get a second chance with ladybugs. Paula Kleintjes, a professor of forest entomology at UW-Eau Claire, says she is frustrated by how many well-meaning Christmas tree farmers intend to avoid pesticide use, but buckle after feeling the pressure of competition from others in the business. Even those who are more comfortable using the chemicals use too much, she says. Instead of targeting one tree or a small patch, they cover the entire plantation. And that really eliminates any future chance of going back to natural controls.

"You get on this treadmill. You rely more and more on insecticides, and because of the damage to natural enemies, it's hard to bring the system back in balance," she says. Kleintjes faults the practice of Christmas tree monoculture – "growing trees like corn" – for creating so many problems. Out West, in indigenous conifer stands, natural diversity in species and ages of trees keep bad bugs in check. "If you have an aphid, it has a harder time finding a host. It doesn't just go three feet [to the next tree]."

Given that they sink a good 10 years of labor and money into an ornamental crop before ever realizing a penny, Christmas tree farmers face challenges different from their corn and timber growing brethren. The answer to the bug wars may lie more in a change in the buying public's attitudes than anything else. It may be true, as growers attest, that the majority of shoppers find it hard to accept less than the storybook Christmas tree. It may also be true that shoppers have no idea how many chemicals have been sprayed on their purchase. Perhaps a segment of the Christmas tree purchasers would settle for a less perfect tree or the green marketing of "organic" trees given the option.

Kleintjes once did a study. On a choose & cut balsam farm with aphid damage, shoppers had come in November to pick out a tree they planned to buy toward Christmastime, Kleintjes randomly selected a tree close to the one the shopper had tagged. She measured its height and diameter, its density and curled shoots. What she found was surprising. While preferred trees were taller and fuller, insect damage wasn't a factor. "I found there was no difference in damage between the chosen tree and the unchosen tree," even though 40 percent of the shoots had been gnawed by the bugs, she says.

Kleintjes believes that choose & cut farmers can grow and sell their trees without using pesticides. It might be harder for growers who cut early and ship trees long distances as damage might be more apparent over time, she says.

There are farmers who sell injured trees for less, assuming that the public seeks perfection. Don Carney, who has refused to use herbicides, is one, and calls his balsams "somewhat rougher" as a result of denser weeds and the closer mowing necessary. In Sturgeon Bay, retired forester Harry Porter hasn't treated his white and Black Hills spruce for the Eastern spruce gall aphid, and will let some of them grow to timber height instead, he says. Other, smaller trees will be sold for about 75 percent of the normal asking price. Porter finds that buyers are usually very choosy about their Christmas trees.

"The person who wants an organic tree is in the minority," he says. "So practically, you've got to consider the average consumer. You will cover 80 percent of the customers with a dense, sheared, colored Christmas tree. These things are what the average person is looking for."

On a cloudy day, late last summer, Ken Appel spent ten minutes trying to explain exactly why one Scotch pine was superior to another. The first tree, I thought, was beautiful – one of the few that hadn't been bothered by the Zimmerman moth. It was dark green, about seven feet tall, and displayed that fluffy Scotch pine fullness. But to Appel's eyes, it was defective.

He pointed out an ever so slight indentation on its right side, a sign of poor shearing. He showed me a couple of small openings toward the tree's bottom, which interfered with the uniform shape. For those reasons only, it was a Number 2, an inferior specimen, and would fetch a smaller price.

Nearby stood another pine, almost identical to the first, which had been shorn perfectly into a completely symmetrical cone. In the parlance of Christmas tree growers, its foliage was dense and its pockets were tight, meaning it had no holes. Its leader, the top stalk on which angels perch, was smack in the middle. This one, Appel says, will be a Number 1.

"Retailers tell you, 'I don't want any trees with holes in them,'" Appel says. "And it's critical to them when they're selling a couple hundred trees on a retail lot. They're competing with some huge Christmas tree sellers."

But getting to the point where most trees are perfect Number 1's exacts a toll. Pesticides and the equipment needed to spray them, helicopters sometimes included, are very pricey. Many farmers haven't even analyzed the true long- and short-term costs and benefits of chemicals versus natural control before they spray, Kleintjes has found.

And then there are the environmental issues like changes in groundwater quality or change in native animal and insect populations, which may be even harder to measure. On a sandy pine field regularly treated with pesticides over the years, with the prospect of more to come, it is encouraging to see a frog jumping high in the air. But, the professor wonders, if nobody had sprayed, would there have been more?

Staff writer Katherine Esposito delves into current environmental issues from our Madison office.