Sweet corn is an appropriate name for the crunchy vegetable that makes Fourth of July picnics complete. According to the University of Illinois, there are three types of sweet corn: normal sugary, sugary enhancer and super sweet. Whichever of these hybrids you choose, sweet corn is best when you eat it soon after harvest. For healthy corn crops, provide your plants with plenty of sunlight, fertilizer and space. Unfortunately, there are several common problems you may face when growing sweet corn.
The corn earworm is a common problem that often attacks sweet corn. Prevention is the best remedy, according to the University of Illinois. When the silk first appears, wrap a rubber band around the ear's husk or clip it shut with a clothespin. You can also drop half of a medicine dropper full of mineral oil into the silk tube to reduce the damage caused by the corn earworm. The corn rootworm beetle can also plague your sweet corn plants. This pest must be controlled when the silk first forms. Other insects that can affect sweet corn include the flea beetle and the European corn borer.
Too Few Plants Won't Produce Good Corn
Corn of all types requires a good-sized growing bed because of the way the kernels become pollinated. Plant at least four rows of sweet corn to enable the pollen to drift from plant to plant and create the best-tasting harvest, according to USAGardener.com.
Soil, Water and Nutrition Problems
If you plant sweet corn too early in the spring, before the soil reaches about 60 degrees F, not all seeds will germinate and seedlings can become stunted or damaged by a late frost. Keep your sweet corn well watered, especially during hot, dry weather when the plants have tassels that need pollination; too little water can result in missing kernels and possibly undersized ears. The University of Illinois recommends fertilizing sweet corn with a plant food that is high in nitrogen when your plants are 1 foot to 18 inches tall. It's also important to keep weeds pulled from your corn patch so the plants don't have to compete for water and nutrients. Mulch can help to both keep weeds away and conserve the moisture in the soil.
Other Types of Corn Can Cross Pollinate
All sweet corn varieties have weak pollen, which makes it possible for the pollen of other corn species to take over, causing the kernel to become tough and starchy, like the field corn growing nearby. To prevent this unfortunate occurrence, plant any other type of corn at least 500 feet from your sweet corn patch, as corn pollen drifts when the wind blows. If your neighbors are growing another variety and your sweet corn's flavor disappoints you, tell them about sweet corn for next summer's garden.
Sweet Corn Diseases
Stewart's wilt and smut are diseases that sweet corn can develop. Wilt is a bacterial disease that the flea beetle helps to spread; controlling this insect will help prevent disease. Some varieties of sweet corn are resistant to wilt. Smut is a fungal disease that affects the kernels. White varieties of sweet corn are more susceptible to smut, especially during very hot, dry weather. The disease causes galls, or "bumps" from the ears---pinch them off and then burn them or dispose of them far from your corn patch.