Until a few years ago, we picked all the blueberries we wanted from our mature bushes with minimal competition from birds. Then a memo went out in birdland that we had the best berry brunch for miles around, and we started seeing many more berry-eating birds on our blueberries, raspberries and blackberries.
It was time to devise a practical strategy for protecting our berries from birds, which I wrote about ten years ago in bird control in the garden. There have been several interesting developments since then, with studies revealing new information about old and new methods for deterring berry-eating birds.
Identifying Berry-Eating Birds
Until I started using the Merlin Bird ID app from Cornell University to identify birds by sound, I seriously underestimated the diversity of berry-eating birds in my yard on a summer day. There are at least a dozen species! Most are big birds with appetites to match, and many eat insects and seeds when berries are not available. None are threatened species. About half of the berry-eating birds in my yard live here year-round, while the rest spend winters in Mexico and Central America.
Except for boundary issues with the berries, I’m glad they are here. The bright red cardinals and scarlet tanagers are beautiful to see, and I admire how the male catbirds and wood thrushes keep watch while their mates enjoy leisurely lunches. The robins are another story, ruining as many berries as they pick. Not everything in nature is nice.
New Methods for Deterring Birds
The same is true in the world of bird deterrence. At airports, military bases and other locations where birds pose an imminent danger, powerful green-light lasers are being used to make them move on. Please do not try this at home! Though you can buy the devices online, when improperly used the lasers can blind people and birds and catch things on fire. They’re good for preventing plane crashes, not so good for protecting berries.
In the latest spin on scarecrows, air dancers that bop in the wind are being used to deter birds from commercial berry and corn fields. Air dancers are expensive to buy and electricity is required to keep them inflated, but they do deter birds from a limited space. However, they are no more effective than scare eye balloons, which are much cheaper and often work well in yard-size plantings.
The biggest development in bird deterrence is a story of sour grapes. For 50 years gardeners have used grape Kool-Aid to deter birds, which sounds hokey but it’s not. Grape Kool-Aid contains a chemical called methyl anthranilate that birds find disgusting. Methyl anthranilate forms the basis for several new chemical bird deterrents used to deter birds from agricultural fields and golf courses. These products are costly, but they are effective, humane, and safe for the environment.
For gardeners, a few packets of grape Kool-Aid will help protect berries from birds. Simply dissolve a packet in a pump spray bottle of water then spritz the plants daily when you go to pick, and always after rains. It is best to combine grape Kool-Aid with a visual deterrent like a scarecrow, spooky balloon, reflective tape, or loose plastic bags that move in the wind. Birds will quickly learn that the berries next to the scarecrow are the yucky ones. Grape Kool-Aid does cut down on predation, and I have noticed no residual grape taste on blueberries and black raspberries treated with Kool-Aid.
Excluding Birds with Covers
The ultimate way to prevent bird damage to berries is to net, screen or fence them out. Early on we tried using black mesh bird netting, but hummingbirds kept getting stuck in it and freeing a panicked hummingbird is no fun. Many gardeners in my area build chicken wire structures to protect their blueberries, which have the added benefit of excluding squirrels. I tried using covers made of lightweight insect netting, which failed to control birds coming up from the ground.
But what about row cover, which hides the berries from view? As Roger designed and built a frame for our best blueberries using conduit pipe, we realized that we could get great coverage all the way to the ground from 10-foot-wide row cover attached with snap clips.
Fort Blueberry is a huge success. It’s a few degrees warmer in there, though the berries don’t seem to mind. I love being able to let the fruits fully ripen on the plants, and not encountering slashed or poopy berries as I pick. It’s also cool to be inside the cube and hear birds feeding on unprotected bushes on the other side. The row cover will come off in three weeks, when the harvest ends, to be stored until next year. Ditto for the grape Kool-Aid.