Blackberries offer a significant harvest reward for the home gardener, but their sweet, dark fruit is equally appealing to many common bird species. Birds like blackbirds, robins, starlings, and jays can quickly decimate an entire patch, often pecking berries before they are fully ripe, leading to substantial yield loss. Protecting a blackberry patch requires proactive planning and understanding avian behavior. Effective strategies range from completely blocking access to creating an environment birds prefer to avoid.
Physical Barriers: The Most Effective Defense
The most reliable way to secure a blackberry harvest is through physical exclusion, preventing birds from reaching the canes. This involves the strategic use of bird netting, which acts as a complete barrier between the fruit and the birds. Simply draping netting directly over the canes is ineffective, as birds can reach through the mesh to peck the fruit and the net can tangle in the thorny canes.
A rigid support structure, such as a fruit cage built from PVC pipe, rebar, or metal conduit, is necessary to suspend the netting above the fruit. This framework ensures the net remains taut and away from the berries, creating a gap that prevents birds from reaching the fruit. A mesh size of approximately 3/4 inch (19 mm) is recommended. This size is small enough to exclude most common berry-eating birds while allowing air circulation and light penetration.
Durable netting materials like woven polyethylene (PE) or UV-stabilized nylon resist tearing and last for multiple seasons. When installing the net, secure the base completely to the ground using landscape staples or by burying the edges. This prevents birds from walking underneath the barrier. A well-designed structure should incorporate an easy access point, such as a hinged door or a section secured with clothespins, to allow for daily harvesting and maintenance.
Sensory Deterrents: Scaring Birds Away
Deterrents that engage a bird’s senses, such as sight and sound, can be useful secondary measures, though they are rarely effective alone. Many visual deterrents rely on the bird’s natural wariness of unexpected movement or perceived predators. Reflective tape, often called flash tape, is a thin, metallic material that creates unpredictable light flashes and movement when stirred by the wind. Shiny objects, like old CDs or aluminum pie tins, function similarly, using glare and movement to disorient approaching birds.
Predator decoys, such as plastic owls or snakes, attempt to trigger an innate fear response. However, their static nature means birds quickly realize they pose no genuine threat. The primary limitation of nearly all sensory deterrents is habituation, where birds become accustomed to a non-threatening stimulus and learn to ignore it. To counteract this, visual deterrents must be moved frequently, ideally every few days, to maintain the element of surprise. Auditory deterrents, including sonic devices that emit predator calls or bird distress signals, can be briefly effective but also suffer from habituation if the sounds are looped predictably.
Crop Management and Timing
Strategic adjustments to the growing and harvesting process can reduce the attractiveness of the blackberry patch. The simplest step is to harvest the fruit immediately upon ripening, minimizing the window of opportunity for birds to feed. Allowing ripe berries to remain on the cane serves as a direct invitation to local bird populations.
Birds often seek out water as well as food, especially during hot, dry periods. Providing a clean, separate water source, such as a bird bath or a dedicated fountain, away from the blackberry patch may divert some birds from the fruit. This fulfills a biological need without requiring them to visit the fruiting area.
Another tactic involves using decoy crops, which are less desirable plants or berries offered in a different area to redirect attention from the blackberries. Planting a patch of inexpensive millet or sunflowers, or providing a dedicated feeder, offers a more easily accessible food source that encourages birds to forage elsewhere. Combining these cultural practices with physical exclusion helps growers secure a greater percentage of their harvest.