Lovable? To look at, perhaps, but raccoons are not welcome visitors to sweet corn plots.
Stealthy critters have their eyes on your sweet corn
Horticulture expert says fencing may be the best control measure
June 25, 2020
MANHATTAN, Kan. – Ward Upham is only half-joking when he says that the official inspector for sweet corn should be the raccoon.
“Every year,” says Upham, a horticulture expert at Kansas State University, “they seem to harvest the sweet corn the day before it is to be picked.”
Upham notes that no matter what gardeners try, raccoons seem to be wily enough to find their way into each year’s crop of sweet corn.
“The only effective control measure I have had success with is either electric or kennel fencing,” he said, drawing from experience in his own yard.
With kennel fencing, Upham says it’s important that the panels are tied tightly so that raccoons can’t squeeze through the corners: “A covering over the top may be needed if the raccoons figure out how to climb the panels. Welded garden fence can also work well for this.”
Electric fencing requires a bit more ingenuity. Upham suggests:
- Use two or more wires. Place the first wire five inches above the ground and the second four inches above the first so that raccoons cannot crawl under or go between without being shocked.
- Fence posts and insulators used for electric fences work well in gardens, too.
- Use a woven electric wire with strands of wire embedded, rather than a solid metal wire. The woven wire is easier to bend around corners.
- Battery-operated fences are more versatile where corn is grown. One set of batteries usually lasts a season.
- Start the charger before corn is ripe. Once raccoons get a taste of corn, they are more difficult to discourage.
- Control weeds near the wire. Weeds can intercept the voltage if they touch a wire, allowing raccoons an entry point.
- Check the wire occasionally to make sure you have current. Tools to measure voltage are worth the money.
Sweet corn earworm
Upham also advised gardeners to be on the lookout for a common pest in sweet corn.
“The earworm moth lays eggs on developing silks at night,” he said. “When the egg hatches, the larva crawls down the silk and into the ear. Feeding starts at the tip of the ear and works down.”
Controlling the sweet corn earworm is challenging as silks continue growing, he said. Gardeners may need to apply insecticides every two to three days, especially in early July during the moth’s peak flight.
“There is a three-week period from silking to harvest, but there is only a two-week period from when the silks appear to when they begin to dry,” Upham said. “Since moths prefer juicy silks and shun those that have started to dry, insecticides are needed the first two weeks of silking.”
Recommendations for effective insecticides are included in the Horticulture Newsletter, which is produced each week by Upham and his colleagues in K-State’s Department of Horticulture and Natural Resources. The newsletter is available to view online or can be delivered by email each week.
Interested persons can also send their yard and garden-related questions to Upham at wupham@ksu.edu.
