Blackberries are a delicious summer fruit, appealing to both gardeners and the local bird population. The sweet, dark berries become an irresistible food source for many bird species as they ripen, and a flock can decimate an entire harvest in a matter of hours. Protecting your blackberry canes is necessary to ensure you get to enjoy the fruits of your labor. Several distinct methods are available to create a barrier between your ripe berries and hungry birds.
Physical Exclusion Methods
Physical barriers are the most effective way to guarantee a full harvest because they directly prevent birds from reaching the fruit. Bird netting is the most common material used for this purpose, but proper installation is crucial for success and to avoid harming wildlife. A polyethylene or polypropylene netting with a mesh size of \(3/4\) inch or smaller will exclude most common berry-eating birds like robins and starlings.
It is recommended to suspend the netting over a frame or support structure rather than simply draping it directly over the blackberry canes. A simple frame can be constructed using materials like PVC pipe, metal conduit, or bamboo poles to create hoops or a cage-like enclosure. This separation prevents the netting from snagging on the thorny canes, which can damage the plant and make harvesting difficult. It also prevents birds from perching on the netting and pecking through the mesh to reach the berries.
The entire enclosure must be completely sealed, as birds will exploit the smallest gap to access the fruit. The base of the netting should be secured tightly to the ground using ground staples, bricks, or a length of PVC pipe to prevent birds from crawling underneath. When installed correctly to exclude all access points, physical netting provides nearly 100% protection for the ripening berries.
Visual and Sensory Deterrents
Deterrents that rely on sight or sound aim to frighten or disorient birds, making the area around the blackberries seem unsafe or unpleasant. These methods are generally less reliable than physical exclusion because birds are intelligent and can quickly become accustomed to predictable threats. For optimal effectiveness, these deterrents must be rotated and combined with other tactics to delay the onset of habituation.
Reflective materials are a common visual deterrent, exploiting the birds’ sensitivity to light and movement. Holographic flash tape, which is a specialized Mylar ribbon, can be cut into strips and tied to the trellis wires or canes. The tape’s movement in the breeze, combined with the unpredictable flashes of reflected sunlight, creates a visual disturbance that birds perceive as a threat or disorientation. Old CDs or strips of aluminum foil can achieve a similar effect.
Predator decoys, such as plastic owls or snakes, also work on the principle of fear, but their static nature quickly gives them away as non-threats. To maximize their short-term efficacy, these decoys should be moved frequently, ideally every few days, to a new location within the patch. Pairing a visual deterrent with an auditory one, like reflective tape that rustles in the wind or a sound device that broadcasts distress calls, can increase the overall impact.
Cultural Practices and Harvesting Strategy
Plant management and timing can serve as supplementary strategies to make your blackberry patch a less appealing target for birds. Proper pruning is an important cultural practice that benefits the plant and indirectly deters pests. Removing dense, old canes and thinning the new growth improves airflow and reduces the amount of sheltered cover available for birds to hide in while feeding.
A well-pruned patch also allows sunlight to penetrate better, which can aid in fruit ripening and reduce the time the berries are vulnerable to predation. The timing of your harvest is another simple strategy to reduce losses. Picking the blackberries just before they reach their absolute peak ripeness minimizes the window of opportunity for birds to strike. Since blackberries do not ripen further once picked, this requires careful observation to ensure you are harvesting at the optimal time.
Offering an alternative food source, a technique known as “sacrificial planting,” can sometimes distract birds from the main crop. This involves planting less-valued berries or grains far away from the blackberries, providing the birds with an easy meal option. While this is a gamble, combining this distraction with the other methods creates a multi-layered defense that increases the chances of a successful, abundant blackberry harvest.