New varieties of sweet corn make growing it easier than in the past. However, it continues to be a plant grown in larger gardens because of its eventual size and the number of plants needed for pollination.
When to Plant
Plant corn in the spring when the soil temperature is 50 degrees F during the day. If the soil is cooler, the corn seed can rot in the ground or have trouble sprouting. Use a soil thermometer, which you can buy at a nursery or garden center. Or, contact your local county agricultural extension office and find out the optimal planting dates for sweet corn in your area.
The correct soil pH for growing sweet corn is 5.8 to 7.0. You may need to add lime or sulfur may to bring your soil into the correct pH range. The pH is a measure of alkalinity or acidity in the soil. Find out the pH of your soil by obtaining a soil sample with the assistance of your local county agricultural extension office, or by buying a pH meter or test kit from a nursery or garden center.
Plant sweet corn seeds 6 to 8 inches apart 1 inch deep. For best results, plant in blocks of four rows 6 to 8 inches apart separated by 36 inches of space between blocks. This allows for good pollination of plants. A number of short blocks is more effective than one or two long blocks.
Corn thrives in soil enriched with lots of compost and fertilizers containing nitrogen. The only way to tell if you have the correct amount of nitrogen or fertilizer in the soil is to consult the soil testing results obtained from a local county agricultural extension office or to use a test kit. Your extension office will tell you exactly how much and what type of nitrogen fertilizer to use for optimal sweet corn production.
Sweet corn should be grown in full sun. Full sun means corn plants should be exposed to at least six hours of unobstructed sunlight each day during the growing season.
Sweet corn has shallow roots that are easily damaged by using a hoe or other tool too close to the root systems. But you do need to remove weeds from around the corn, because they compete with the corn plants by stealing moisture and nutrients.