"They were coming through part of the gate," says a rather amazed Joe Kovach, an Ohio State University scientist who has set up a lushly growing and ostensibly fenced-off fruit and vegetable test garden on an old asphalt parking lot in Wooster in northeast Ohio.
"I actually saw one leave (the garden)," Kovach says. "It pushed its way right out. They were using the wire on the gate as a trap door."
He fixed the hole with some Plexiglass. The rest of the fence, meantime, is working, he said. Deer and woodchucks, too, have lately been spotted around but not inside the garden.
As Kovach talks, a wren sings from a tree nearby. A robin chirps in apparent alarm from somewhere deep in the garden.
The animals are just a few examples of the biological diversity, both helpful to a garden and less so, that Kovach is cultivating. Some of that diversity has to do with the crops themselves, in terms of their types, genes, sizes and fruiting seasons.
And some of the diversity has to do with what, exactly, comes to live in the garden, especially the small things, such as insects, spiders, bacteria and fungi, that often can actually benefit crops.
The goal, ideally, is creating a stable ecosystem, which in a garden can maximize food production while minimizing costs and losses from pests, Kovach says.
"All the same ecological principles apply no matter what ecosystem you're in," he says.
Even in one rising from blacktop. Among those principles: greater diversity means greater stability.
The garden, which covers an eighth of an acre, grows in and on the parking lot of an obsolete, closed dormitory at Ohio State's Agricultural Technical Institute on U.S. 250, about a mile south of downtown Wooster. It's part of a wider Ohio State effort to learn about and improve urban farming.
"We have a lot of abandoned parking lots in the big cities of Ohio, including Cleveland, Columbus, Youngstown and Dayton," said Kovach, who's an associate professor of entomology with the Ohio Agricultural Research and Development Center, which is also part of Ohio State and is located next to ATI. "So we're trying to figure out ways to make that land more productive, and one of the options is to try to grow fruits and vegetables there."
He's testing three growing methods: in pots and in raised beds set on top of the asphalt, and in beds created by taking out strips of the paving.
Kovach is also trying all three methods under high tunnels, which are inexpensive plastic structures that resemble greenhouses and that protect crops from wind and cold.
He's growing kale, apples, peaches, basil, strawberries, raspberries and blueberries, among other crops, with all of them watered by drip irrigation, which Kovach calls "cheap insurance" against drought.
The idea is to compare how all three methods work, how much food they produce, and the costs and labor involved, and then to share the results with urban farmers, says Kovach.
In the end, he says, the work can help people in cities grow fresh, healthy produce in the cheapest, simplest and best way possible -- on otherwise wasted old parking lots.
"But we're also looking at more than that," he says. "We're looking at the implications that growing in a parking lot has on insects and diseases and how the environment there is changed compared to traditional agricultural settings."
The peaches growing in high tunnels on the asphalt, for example, survived this spring's frost without damage. The other peaches didn't, including both the "control" peaches growing on unpaved ground and the ones on the asphalt but not in the tunnels. The asphalt, it seems, captured daytime heat, while the tunnels held it in at night. "I thought there would be some protection (from the combination), but I didn't think it would be this great," Kovach says.
However, a common peach disease called peach leaf curl has appeared. It causes a peach tree to lose its leaves, but then to grow new ones. This weakens the tree but isn't fatal. Typically, farmers prevent it by spraying a fungicide. But "I'm trying not to do anything" to control diseases and pests, Kovach says, "because I'm trying to see what happens" for the sake of the research.
The strawberries in the high tunnels, on the other hand, were ready to pick earlier than Kovach has ever seen. In his previous studies with strawberries, the earliest start of harvest was May 10. "This year we picked on May 2, which is pretty darn early," he says. "Part of that was due to the high tunnels, and part of that was due to the early spring."
He's also using a system called plasticulture with the strawberries. As part of it, the plants are planted in September, not May, yet still bear fruit the next spring. "You save yourself four months but get the same yields," he explains
His raspberries, however, have had a harder time. The established plants that were transplanted into the garden last fall "didn't overwinter well," he says. "We lost a lot to winterkill."
Plus this spring, in a windstorm, the plastic covering blew off the high tunnels and "really beat the hell out of the plants," Kovach says.
Meanwhile, some plant-sucking mites are a more recent problem for the raspberries. They're not uncommon in the greenhouse-like environment of a high tunnel, Kovach noted. But he says he's anticipating the arrival of some different, friendlier mites -- predatory ones that eat pests, not plants.
The blueberries, for their part, are booming, with good pollination and harvest having started two weeks ago. Yields so far are "impressive," Kovach says. But birds, which generally are good to have in a garden because many kinds eat pests, have taken to eating the blueberries, too.
"I haven't had any bird issues in my blueberry plots" in other studies in other locations, Kovach says. "This year we would come out to harvest, and every morning the birds would fly out (of the bushes).
"I'm not sure why there's a difference," he says, but a nearby line of bird-friendly trees may be part of it. He recently installed bird netting over the bushes to stop the losses.
"But we're going to have tons of berries" either way, he says. "And this is on a parking lot, right? And look at the size of those apples already."
What happens the rest of the summer, which will be the project's second full growing season, and its first with all of its cylinders firing, "will really be more sensitive for teasing out any differences between the (three) treatments in terms of yields and pests," Kovach says. "We'll be sampling for insects to see what sort of difference the asphalt makes, and obviously we'll be looking at diseases."
Otherwise, though, "We'll just be letting things balance.
"Right now everything seems to be looking pretty good," he says.