There was a time when growing summer squash meant either growing a yellow crookneck or a green zucchini. Times have changed. There are not only new varieties of yellow summer squash and green zucchini available that feature better productivity and disease resistance, there is also a host of other summer squash varieties that have different shapes and skin colors.
Summer squash is one of the simplest vegetables to grow. The large seeds germinate quickly in warm soils. The plants grow fast, they stay in a bush form so they are more manageable, and they often flower within a month after seeding. And the fruits just keep coming all summer until disease, insects, or you stop them. In fact, their reputation for being so prolific leads many people to keep their car windows and house doors closed for fear neighbors will dump their excess squash on them!
Although they produce abundantly, summer squashes also taste great and make perfect additions to sautes, stir fries, soups, casseroles, and breads.
Summer squash is grouped by fruit color and shape. The yellow crooknecks are one of the most common types grown. Hybrid varieties, such as 'Dixie' and 'Horn of Plenty', improve on the heirloom crookneck varieties with better production and uniformity. Some varieties, such as 'Supersett', have improved disease resistance and uniform fruit color.
If you like yellow summer squash but not the crookneck shape, try some of the straight-neck yellow summer squash. 'Goldbar', 'Gold Rush', and 'Multipik' are newer varieties to try.
Zucchini varieties abound. 'Black Beauty' and 'Grey Zucchini' are two classics. Others to try include 'President' and 'Senator'. For a lighter green zucchini, try the Lebanese, "cousa" type such as 'Magda'.
For a squash of a different shape try the patty pans. These "flying saucers" are similar to other summer squash except for their unique shape. 'Peter Pan' is a hybrid, green, scalloped-shape variety; 'White Bush Scallop' is a white version, and 'Sunburst' is a yellow variety. For something completely different, try 'Eight Ball', a hybrid, round squash that is great for stuffing and baking.
Like all squash and pumpkins, summer squash and zucchini grow best with warm soil temperatures and plenty of water. Although they can be bought as transplants from a garden center, summer squashes are easiest sown direct into the soil once the soil temperatures is above 60° F. In cold weather areas, consider laying down a layer of black plastic mulch two weeks before planting to preheat the soil and then plant into holes poked in the plastic. Amend the soil with a 1- to 2-inch-thick layer of compost before planting.
There are various planting methods you can use. Plants seeds in rows, dropping the seeds about 8 inches apart in furrows about 6 inches deep. You also can plant summer squash in hills or mounds. Plant 6 to 8 seeds in hills or circles spaced 4 feet apart. Thin after the seedlings emerge, leaving the two to three strongest seedlings. If you have heavy or wet soil, raise the hills into mounds about 8 inches high and flat on top. Plant and space the seeds as you would in the hills.
Once they start growing, side-dress plants at first flowering and then monthly with an all-purpose fertilizer to keep the fruits coming. Keep plants well weeded, and once the soil has warmed, mulch with an organic product, such as pine straw. Keep the squash well watered as well.
Most summer squash varieties have separate male and female flowers. Insects, especially bees, are needed for pollination and fruiting to occur. During periods of cold, cloudy weather, the bees may not be flying, and this can result in reduced pollination and fruiting. You can improve the harvest by helping with pollination. In the morning when the flowers are fully opened, go into the garden and swish a cotton swab in the male flower (the one without the enlarged area or ovary behind the flower). Then take the cotton swab containing the yellow pollen and swish it around the female flower (the one with the enlarged ovary behind the flower). This should help insure that the flower gets pollinated, and young squash are bound to follow.
Summer squash is attacked by the same insects that love winter squash and pumpkins. Squash vine borer adults lay their eggs on the squash stems near the ground. The eggs hatch and the young tunnel into the fruits and can eventually kill the plant. Protect your squash plants by covering them with a floating row cover until they start to flower. Place aluminum foil beneath the plant to confuse the adult flies so they can't lay eggs. Surgically remove the young larvae with a sharp knife or inject Btk (Bacillus thuringiensis var. kurstaki) into the plants.
Squash bugs are flat-shelled, brown insects that form groups on the undersides of squash leaves. Their feeding can cause leaves to turn yellow and die. To control squash bugs, lay boards in the garden at night. The bugs will hide under them during the day, so in the morning collect and destroy hiding bugs.
Powdery mildew and various blight diseases attack summer squash. Control these by planting disease-resistant varieties and cleaning up the squash patch well in fall.
Summer squash fruits are best harvested when young and immature, unlike winter squash and pumpkins whose fruits need to mature on the vine before harvest. Begin picking summer squash even while the flower is still attached. The ideal size is 6 to 8 inches long. The more you harvest, the more the plant will produce. Don't let squash get overgrown. Not only will you be at a loss as to what to do with the giant fruit, it will slow down the production of additional squash.
For more information on growing summer squash in your garden, go to the Virtual Vegetable Guide on the Willhite Seed Web site (www.willhiteseed.com).
Q. Each year I have a load of broccoli worms on my broccoli. My wife loves broccoli but won't eat fresh garden broccoli because of these green worms. How can I control them without using toxic pesticide?
A. These worms are most likely cabbage worms. They can be controlled organically in a number of ways. There is a biological control called Bacillus thuringiensis (Bt for short) that is very effective in controlling this pest. It is widely available under the brand names "Dipel" and "Thuricide." It is a bacterial disease that infects only the pest and doesn't harm people, pets, or beneficial insects. Another option is neem oil spray. This botanical control suppresses an insect's desire to feed and halts larval development so insects die before they molt. It too is safe for pets, people, and beneficial insects. By the way, if you soak broccoli in a big bowl of salted water, keeping the head submerged with a heavy plate, the cabbage worms will float to the top. Then you can scoop them up (when your wife isn't looking) and destroy them and enjoy eating the broccoli.