CORVALLIS, Ore. — Freshly planted vegetable gardens can quickly become magnets for trouble.
Weeds, slugs, aphids and caterpillars often seem to appear overnight and can damage young plants before gardeners notice.
If you haven’t planted yet, prepare the soil and wait one to two weeks for weeds to sprout. Hoe them out when they are small — about the time two true leaves appear. Allow another flush of weeds to germinate, remove them again and you’ll have a cleaner start for vegetables. Continue weeding until crops are large enough to shade new weeds.
As you weed and plant, watch closely for pest and disease problems. Early detection makes management easier.
Slugs
Slugs are currently active and especially attracted to lettuces and members of the cabbage family, though they will feed on almost any vegetable seedling. Check under rocks, stepping stones and other moist hiding places.
Management options include:
- Drop slugs into a bucket of water.
- Use iron phosphate bait sold under names such as Sluggo.
- Set traps by burying a margarine or yogurt container to just below the rim and filling it with beer to collect slugs overnight.
Cucumber beetles
Cucumber beetles are about a quarter-inch long and yellow with black spots or stripes. They chew holes in leaves and can kill emerging cucumber and squash seedlings.
To manage cucumber beetles:
- Maintain good garden hygiene by cleaning up at the end of the season and keeping beds tidy.
- Use floating row covers immediately after planting, draped over hoops and sealed at the edges.
- Remove row covers once crops begin flowering.
If beetles are already present, consider planting fresh transplants and covering them right away. Pesticides are generally ineffective because cucumber beetles move quickly.
Aphids
Aphids are small, soft-bodied insects — often green, but sometimes black, gray or red — that feed by sucking juices from leaves and producing sticky honeydew. They tend to cluster on the undersides of foliage.
For mild aphid problems:
- Squish insects by hand.
- Wash them off with a strong stream of water.
For moderate infestations, consider insecticidal soaps, which must directly contact the aphids to work. Encourage natural predators such as ladybugs, lacewings and hover flies by avoiding broad-spectrum pesticides and planting a diverse mix of flowering species.
Aphids are usually most troublesome in July and August, so broccoli, cabbage and other early brassicas may be harvested before populations build.
Cabbage white butterfly
White cabbage butterflies lay eggs on the undersides of leaves. The larvae — green caterpillars often camouflaged against foliage — can tunnel into cabbage heads and damage other brassicas.
Management options include:
- Use row covers early in the season to prevent egg-laying.
- Apply insecticidal soaps or products containing Bacillus thuringiensis (Bt) if larvae are present.
- Plant a new crop under a row cover and removing it only for harvest.
Previously titled Use vigilance in controlling problems in the vegetable patch
