Ideal Climate and Soil for Corn Growth

Temperature

• The soil temperature must be at least 60 degrees Fahrenheit for corn seeds to germinate. Seeds decay and fail to germinate in cold soil. To protect plants from stunting or killing frost, wait until two weeks after the last expected frost date to plant seeds. Wind damage or temperatures above 95 degrees F can result in corn ears with fewer kernels. Besides proper temperatures, corn plants need eight to 10 hours of sunlight every day.

Soil Preparation

• Although corn tolerates a variety of soil types, it prefers well-drained, rich soil with a pH between 6.0 and 6.5. To add beneficial micronutrients, mix well-rotted manure or compost with the top 6 to 8 inches of soil. You can add elemental sulfur one year before planting to lower the soil pH, or add lime two to three months before planting to raise the soil pH. The amount of sulfur or lime depends on the desired soil pH. For example, 1.5 pounds of elemental sulfur per 100 square feet of soil mixed 6 inches deep decreases the pH from 7.5 to 6.5, according to Colorado State University Extension.

Fertilizer

• A soil test indicates whether the soil lacks important nutrients for corn growth, such as nitrogen (N), phosphorus (P) and potassium (K). If you do not have results from a nutrient soil test, you can apply 10-10-10 fertilizer to the soil before planting. Mix in 6 pounds of 10-10-10 fertilizer per 100 row feet, as recommended by the University of Georgia College of Agricultural and Environmental Sciences. During the growing season, switch to 34-0-0 or other low-phosphate fertilizer to avoid phosphate buildup and runoff, which can pollute nearby streams and lakes. For example, you can apply 1 pound of 34-0-0 fertilizer to trenches along the side of each row once or twice in the spring and summer.

Moisture

• Corn plants should receive 1 inch of rainfall every week. If it does not rain, you should water corn plants every week with enough water to soak the top 6 inches of soil. Corn plants need adequate moisture to produce fully developed ears of corn with tassels and silks. Too much or too little water interferes with ear and kernel development, which occurs throughout the plant's growth, and pollination, which occurs 69 to 75 days after shoots emerge from the soil, according to the University of Wisconsin Extension. To prevent rust disease, which causes orange streaks on corn leaves, water early in the morning and use a soaker hose to avoid wetting the leaves.

Planting

• Proper seed depth and spacing help corn plants make the best use of ideal climate and soil conditions. When the soil reaches 60 degrees F, plant groups of three seeds 1 inch deep and 12 inches apart in rows 30 to 60 inches apart, as recommended by the University of Minnesota Extension. Wind evenly distributes pollen in groups of parallel rows. One long row of plants, however, results in uneven pollination and incomplete kernel rows during ear development. Proper climate and soil conditions ensure the development of pollen-producing tassels at the tops of the plants and pollen-receiving silks in the husks of the future ears.