Vegetable Gardening (58 page)

Anthracnose:
This fungus attacks many vegetables, but it especially loves cucumbers, muskmelons, and watermelons. During warm, humid conditions, the leaves develop yellow or black circular spots, and fruits develop sunken spots with dark borders. To slow this disease, space plants a few feet further apart than normal so the leaves can dry quickly in the morning. Also, destroy infected leaves and fruits. You also can avoid this disease by rotating crops yearly.

Bacterial wilt:
This devastating bacterial disease is found mainly on cucumbers and muskmelons. Sure signs of the disease are well-watered plants that wilt during the day but recover at night. Eventually, the plants will wilt and die. If you cut open a wilting vine, the sap will be sticky and white. To control this disease, plant resistant varieties and control the cucumber beetle, which is the pest that spreads bacterial wilt in your garden.

Cucumber beetle:
This 1/4-inch-long, yellow- and black-striped (or spotted) adult beetle feeds on all cucumber-family crops. The adults feed on the leaves, and the young larvae feed on the roots. Cucumber beetles are the chief culprits for spreading bacterial wilt and virus diseases; they're especially devastating to young plants.

To control cucumber beetles, cover young plants with a
floating row cover
(a cheesecloth-like material that keeps insects out but lets in air, light, and water; see Chapter 21 for details) as soon as they emerge. After the plants flower, remove the row cover so bees can pollinate the flowers. You also can apply a botanical spray such as pyrethrin on the adult beetles.

Squash bug:
These 1/2-inch-long, brown or gray bugs love to attack squash and pumpkins, especially late in the growing season. The adults and smaller-sized young feed on leaves and stems, sucking out the plant juices. These insects move in packs, and their feeding can quickly stunt your plants. Squash bugs usually start laying eggs when the plants begin to vine. To control these pests, crush the masses of reddish-brown eggs on the underside of leaves. Also, rotate crops and clean up plant debris in fall where the squash bugs
overwinter
(live through the winter).

Squash vine borer:
This pest mostly affects squash and pumpkin plants. In early summer, the adult moths lay their eggs on stems near the plants' bases. After the eggs hatch, white caterpillars with brown heads tunnel into the plants' stems to feed. They can cause well-watered vines to wilt during the day and eventually die. Look for entry holes and the sawdustlike droppings at the base of your plants to see if vine borers are present. Consider growing butternut squash, which is less susceptible to vine borers.

To control these pests, try one of the following methods:

• Slit your plant's stem lengthwise from the entry hole toward the tip of the vine with a sharp razor, and physically remove the caterpillar. Then cover the stem with soil; it will reroot itself.

• Cover the plants with a floating row cover until they begin to flower, which keeps the moths from laying their eggs.

• Inject Bt (
Bacillus thurengiensis;
a naturally occurring bacterium that attacks only caterpillar-family insects) into the stem with a syringe to kill any young caterpillars.

Harvesting your vining crop

One of the keys to a good cucumber-family crop is harvesting the fruits at the right time. Here are some guidelines for you to follow:

Cucumbers:
The fruits are best when harvested small — slicers when they're 6 inches long and picklers when they're 4 inches long. If they grow too large and begin to turn yellow, the seeds inside the cucumber are maturing, and the plant will stop producing flowers and fruits. Pick off and compost any large fruits that you missed so you can keep the young ones coming.

Summer squash:
Harvest summer squash as small as possible, even if the flower is still attached. Doing so helps you avoid the glut of zucchinis that always happens by midsummer.

Winter squash and pumpkins:
Harvest winter squash and pumpkins after they change to the expected color of their variety and their skin is thick enough that your thumbnail can't puncture them. If you want to store winter squash and pumpkins through the fall and winter, don't let them get nipped by frost, or they'll rot. Leave 2 inches of the stem attached for best storing.

Deciding when to harvest muskmelons can be tricky. After their skin color turns from green to tan and the
netting
(the ribbing on the skin that's slightly raised) becomes more pronounced, gently lift the melons up. If they're ripe, the fruits will slip, or easily detach, from the vine. If you aren't sure, harvesting early rather than late is better because most melons continue to ripen off the vine.

Watermelon harvesting is even more complicated because it's often not obvious when the fruits are ready to harvest. Follow these tips:

Watch for changing colors:
Two signs that it may be time to harvest watermelons are when the skin color turns from shiny to dull and when the color of the spot where the watermelon rests on the ground turns from white to yellow.