Hostas are popular additions to gardens for their beautiful leaves and fragrant flowers. Unfortunately, they are also tasty treats for a number of garden pests. Below are a few suggestions for how to keep your hostas safe from insects, rodents and other pests.
Stopping Slugs and Snails
Slugs and snails are the most notoriously problematic pests for hostas as they eat both the leaves and roots. The traditional and most effective manner of removing slugs and snails from your garden is to go out at night and collect them manually. For this, you need a light to spot them with and a container to put them in.
You can also use poison pellets to dispose of slugs and snails. The problem with these is that the poisons also affect outdoor pets like dogs and cats, and even children. A poison that is less toxic to pets is aluminum sulfate. Scatter the crystals of this poison on the soil around your hosta to act as a contact poison.
Barriers can be an effective method of deterring slugs and snails. Sharp ground covers—including sand, volcanic rock, broken eggshells, crushed oyster or scallop shells—and diatomaceous earth can block the mollusks from reaching your hostas. Continuous strip barriers of copper or aluminum tape can stop slugs and snails with a chemical reaction that causes them to desiccate. The problem with a barrier is that the leaves of the hosta often extend past the barrier, allowing the slugs and snails to use the leaves as a bridge to avoid the barrier.
Alternately, try placing a few bowls of beer around your garden at night. The snails and slugs will be attracted to the scent and climb into the bowls, drowning themselves. Dispose of the contents of the bowls in the morning.
Cutworms are small, soft bodied worms that will eat leaves and roots of your hostas. To prevent these pests from reaching your plants, install a collar around each stem. The collar should be made of cardboard or plastic, extending 1 inch into the soil and protruding 2 inches above the soil. It should rest about 3/8 inch from the stem. If this is insufficient, try using proprietary insecticides.
Driving Off Deer
Deer will eat your hostas right to the ground from spring through fall. The only surefire way to keep deer out of your garden includes 10 foot walls and trained guard dogs. If you have a major deer problem, consider creating sequence of barriers spaced close together so that the deer can not get a running start between them, or hang shiny things from the trees as the animals will be deterred by their own reflections.
Alternately, try offending multiple senses. Coyote urine or tiger dung will drive deer away with their smell, and a spray of soapy water or hot pepper wax on the leaves will make them taste bad.
Most rodents will chew up the leaves of your hostas, but voles will actually eat the roots. Monitor your hostas in the winter if you keep them in a greenhouse, as these are popular wintering spots for rodents because of the warmth.
Do not layer on mulch too thick as it forms a home for burrowing rodents. Stick with an inch or less under most circumstances. If rodents move into the area despite your best efforts, try traps and poison baits.