Blueberry bushes promise a rewarding harvest, but the developing fruit attracts various bird species. Birds like robins, starlings, and cedar waxwings can quickly strip a bush, significantly reducing the crop for home gardeners and small-scale growers. Protecting the ripening berries requires a proactive approach involving strategies designed to deny access or cause alarm. Effective bird control ensures the effort spent cultivating the bushes results in a full harvest.
The Primary Strategy: Physical Exclusion
The most reliable method for protecting blueberry bushes involves creating a physical barrier that completely excludes birds from the plants. Exclusion methods are the most effective because they do not rely on startling or confusing wildlife, which often leads to birds becoming accustomed to the deterrent. This strategy centers on the proper application of bird netting or the construction of specialized cages.
Bird netting should be made from a durable, UV-resistant material like high-density polyethylene (HDPE) to withstand sun exposure and last for several seasons. The mesh size is an important consideration. A standard opening of a half-inch (1/2 inch) is effective for blocking most common berry-eating birds while still allowing sunlight, air, and rain to pass through. Larger mesh sizes, such as three-quarters of an inch, may allow smaller birds to reach the fruit by stretching their necks through the openings.
To prevent birds from perching on the netting and pecking at the fruit, the net must be supported by a frame or structure. Building a simple cage using PVC pipe, wooden stakes, or metal hoops creates a necessary air gap between the netting and the bush canopy. This structure also makes it easier to access the plants for harvesting and maintenance tasks. Securing the netting flush with the ground is equally important, as this prevents birds from hopping or walking underneath the barrier to access the lower fruit.
Secondary Methods: Visual and Acoustic Deterrence
Methods that attempt to deter birds through sight or sound are less reliable than physical barriers but can provide supplementary protection. These techniques rely on exploiting a bird’s natural wariness of predators or sudden movement. Reflective visual deterrents, such as metallic flash tape or holographic ribbons, are designed to flutter in the wind and create confusing flashes of light. These devices work best when strung in parallel rows slightly above the bushes so they move freely.
Visual predator decoys, such as molded plastic owls or hawks, attempt to trigger a fear response in feeding birds. However, birds are intelligent and quickly recognize that a static object poses no actual threat. To overcome rapid habituation, decoys must be moved frequently, ideally every few days, to a new location and orientation. Combining movement with the visual element is more successful, which is why devices like inflatable tube men or kites shaped like raptors can have a temporary benefit.
Acoustic deterrents utilize sound to make an area appear unsafe or undesirable for foraging. This includes specialized devices that broadcast recordings of predatory bird calls or the distress calls of the specific berry-eating species. For these methods to remain effective, the timing, pitch, and location of the calls must be randomized. Birds quickly learn to ignore predictable sound patterns, so varying the sequence and volume is necessary to maintain the illusion of danger.
Preparation and Timing for Success
The effectiveness of any bird control strategy depends on precise timing and consistent maintenance throughout the ripening period. Protection should be installed well before the berries begin to fully ripen and turn blue. The ideal window is when the fruit has formed and is just beginning to show a blush of color change, signaling the berries are becoming sweet and attractive to birds. Waiting until the berries are fully ripe often allows birds to establish a feeding pattern that is difficult to break.
Once the protection is in place, it must remain until the final harvest is complete. Netting should be securely fastened to the support structure and anchored to the ground to prevent wind from creating gaps or blowing the material off the plants. Regular inspection is necessary to check for small tears that could allow a bird entry or to ensure no birds have become trapped within the enclosure. Promptly repairing any damage preserves the barrier’s integrity and prevents harm to wildlife.
When the harvest season is over, the protective materials should be removed, cleaned, and stored in a dry, dark location. Proper storage prevents UV degradation and extends the lifespan of the netting, ensuring it is ready for deployment the following year. Taking down the barriers also allows beneficial insects, like pollinators, to access the plants more freely and permits general garden maintenance during the off-season.