problem solver

Tobacco hornworm
Manduca sexta

IDENTIFICATION — These 3- to 5-in.-long giants of the caterpillar world have a large harmless spike, or horn, on their tails. Their green color blends into the foliage of tomato and tobacco plants, some of their favorite foods. They will also attack plants in the nightshade family, such as datura, petunia and nicotiana.

DAMAGE — In early to midsummer, caterpillars can quickly strip a plant of foliage and may sometimes even chew on green tomatoes.

CONTROL — If there are just a few caterpillars on your plants, handpick them. If numbers are larger, spray Bt on affected leaves only. Thuricide, which contains the kurstaki strain of Bacillus thuringiensis, works well on tobacco hornworm and is safe to spray right up to harvest, but be sure to wash fruit well before eating. Or grow alyssum, dill or Shasta daisy to attract braconid wasps, which lay dozens of eggs within each larva, parasitizing and killing it.

nasturtiums in salads

Not only are nasturtiums beautiful garden flowers, they’re edible! Add leaves and flowers to salads and summer pizzas for a spicy, peppery taste. They’re also high in vitamin C. The bright flower color will surely add a punch to your cooking.

Plant some nasturtiums in a container by the kitchen for easy access. Grow them in full sun in moist, well-drained average soil. Of course, if you’re going to eat the flowers or leaves, don’t use pesticides or chemical fertilizer on or near the plants.

problem solver

Blossom-end rot on peppers

IDENTIFICATION — Blossom-end rot is a common problem with peppers, as well as tomatoes, melons and squash. It starts out as a round, sunken, soft spot at the end of the pepper and grows steadily larger. Blossom-end rot is caused by a calcium deficiency in the developing fruit. The calcium deficiency is caused by fluctuating moisture and too much nitrogen that stress the plants. Deep cultivation and salt burn can also cause stress that may result in blossom-end rot.

CONTROL — To keep your fruits and vegetables healthy, mulch around them to keep the soil evenly moist and cool. Feed the plants with a low-nitrogen fertilizer at planting and give them about an inch of water per week. If you still have problems, spray your plants with a calcium chloride solution that you can find at your local garden center. Start spraying when the fruits begin to form and continue on a weekly basis for four weeks. Be sure to wash the fruit as you normally would before eating.

problem solver

Radish root maggot
Delia planipalpis

IDENTIFICATION – The radish root maggot can be a particularly rude pest in the vegetable garden. These pale larvae tunnel through the root flesh of many root crops, leaving unsightly, slimy brown trails. Members of the mustard family, including radish and turnip, are most often affected. This damage isn’t visible until the crop is harvested and prepared. Wilting of the foliage may be seen before harvest.

LIFE CYCLE – The radish root maggot is the larval stage of a tiny fly. The adult female fly lays her eggs on the leaves of host plants. The eggs hatch and the larvae then drop to the ground and begin tunneling into the root tissue. They survive winter as pupae that look somewhat like seeds in the soil.

CONTROL – Once your radish or turnip crop has been damaged, there is nothing you can do to save it. At this point, pull all the plants and throw them away. Don’t compost them because the maggots will complete their life cycle in your compost pile and be ready to infest the next crop. The best control is prevention. In the spring after you sow seeds for radish, tent the planting with floating row cover, available at your garden center. Tenting will prevent the adult flies from laying eggs on the leaves. Be sure to cover the entire row and seal the edges with soil or rocks. Keep the radishes covered during the entire growing season. Rotating crops with non-mustard crops like tomatoes, beans, peas or even herbs also helps discourage this pest, as well as many others.

pest watch

Tobacco hornworm
Manduca sexta

IDENTIFICATION – These 3- to 5-in.-long giants of the caterpillar world have a large harmless spike, or horn, on their tails. Their green color blends into the foliage of tomato and tobacco plants, some of their favorite foods. They also eat plants in the nightshade family, such as datura, petunia and nicotiana.

DAMAGE – In early to midsummer, caterpillars can quickly strip a plant of foliage and may sometimes even chew on green tomatoes.

CONTROL – If numbers are small, handpick caterpillars; spray Bt on affected leaves only (thuricide, which contains the kurstaki strain of Bacillus thuringiensis, works well on tobacco hornworm and is safe to spray right up to harvest, but be sure to wash fruit well before eating); grow alyssum, dill or Shasta daisy to attract braconid wasps, which lay dozens of eggs within each larva, parasitizing and killing it.