If not carefully watched, the beauty of your rose bush can quickly fade with the presence of some common but damaging pests. A wide range of options are available for treating the harmful insects ranging from natural to chemical control. Protect your plant from pests by treating them early and enjoy your rose bush for seasons to come.
Spray the underside a rose bush's leaves with water every 7 to 10 days to remove spider mites and their webs. Purchase and release the predatory mite Phytoseiulus persimilis onto heavily infested rose bushes. Spray the leaves with insecticidal soap and horticultural oil, which will destroy the mites on contact.
Drown small snails by placing a small amount of beer into a tuna fish can and placing it beneath the infected rose bush. Remove large snails by hand picking the pest and placing them into a bucket. Release the snails away from your landscape or discard them in the garbage.
Remove thrips from a rose bush with a homemade soap solution. Mix 1 tablespoon of mild dishwashing soap to 1 gallon of water. Pour the solution into a spray bottle and liberally spray the infected bush. Apply the spray early in the morning.
Wash aphids away with a stream of water from the garden hose. Wear gloves and physically remove them when there is a small population. Treat aphids with chemicals such as Orthene or Malathion, readily available at garden centers. Use an organic insecticidal soap, such as Safer Soap, to remove aphids.
Hand pick caterpillars that are rolled up inside a leaf. Remove any leaves where caterpillars are visible. Keep the ground beneath the rose bush clean to prevent caterpillars from making a home there. Spray the area with a solution of ammonia and water to repel the pests.
Repel nematodes by under-planting marigolds or alliums. Fumigate soil where nematodes persist by adding methyl bromide. (The common recommendation is 2 pounds per 100 square feet, then cover with plastic.)