The shallow water of a backyard fishpond creates the perfect dinner table for a hungry heron. The birds simply stand in the low water and feast on succulent fish. Herons can wipe out the effort and expense of a water garden fish in a single sitting. Keeping herons out of garden ponds requires effort and vigilance on the part of the homeowner. A number of humane methods exist to discourage foraging. Never harm any type of heron since many are considered protected species.
Purchase a section of pond netting to completely cover the pond. Select a size large enough to drape over the plants along the edge of the garden. Secure the edges of the netting with rocks to prevent the bird from sticking his head under the net for a snack. This also protects the bird from getting tangled in the netting.
Install a freestanding wrought iron plant hanger near the pond's edge. Hang a long windsock on a hook. The movement of the windsock often discourages birds from visiting by tricking the heron into thinking another bird has already claimed the pond.
Place a bird-shaped lawn ornament such as an owl, crane or another heron. Many homeowners choose to incorporate the decoration into the garden décor by selecting an ornament that matches the fish pond theme. The bird should be tall enough to make the heron think the bird is real. Some garden centers make wooden or plastic cranes attached to a small spring that moves gently in the wind.
Increase the density of submerged and floating pond plants. Plants provide needed shelter for the pond fish and also limit the view from way up in the sky. Dense plants also give the fish a fighting chance to hide when the heron pays a visit to the pond. Herons are notorious for revisiting a backyard pond year after year. Hiding the water may discourage a future visit.
Drive stakes about 2 to 3 inches into the soil right outside the rock edge of the pond. Secure fishing line about 5 inches off the ground level. When the heron lands and walks toward the pond, he'll bump into the fishing line. If the bird can't move forward, he hopefully fly away to greener pastures.
Get a dog to patrol the backyard. There's little chance the dog will catch the heron and the bird might be scared enough to never return to your backyard garden pond again.