How to Grow Sweet Corn

STEP 1 Pick a Sunny Spot and Break-Up the Soil Corn does not have a very deep root system, so be sure to plant in a spot that's in full sun yet sheltered from the wind. A good blast of wind can flatten a corn plant. Prior to sowing the seed, it's best to amend the soil. Begin by using a garden tiller to break up the planting area. If the soil is hard, make several passes over it until it's sufficiently loosened. Next, add the first round of composted topsoil and manure, then spread it with a rake until it's evenly distributed. STEP 2 Add the Fertilizer Corn requires lots of nitrogen, so this need should be addressed with fertilizer prior to planting. First, check the soil temperature, then add nitrogen-rich fertilizer for ideal corn-growing conditions. Select a mixed fertilizer with a 10-10-10 formula – that is, 10 percent nitrogen, 10 percent phosphorus and 10 percent potassium; and add at a rate of 4 cups per 100 feet of planting row. Use a light garden tiller (or a garden fork) to work the fertilizer into the soil about 3 to 4 inches deep. STEP 3 Soak the Seeds First Sow sweet corn seed in full sun when the soil warms to between 60 and 95 degrees Fahrenheit. Sweet corn does not germinate well in cold soil and in low temperature will die. Sweet corn seeds can appear shrunken and shriveled; before they can germinate, they must slowly plump up with water. To help them along, soak dry seeds in water at room temperature overnight before planting. More Planting Tips: In the warmer climates, direct-sow seeds in mid-May: The cobs should be ready for picking in late August or September. In cooler climates, sow the seeds under glass in mid-April to early May, then plant out in late May to early June. Any seedling transplants should be started in peat pots three weeks before you are ready to set them out. To start seedlings indoors, sow 2 seeds — each about an inch deep — in 3" peat pots. To help them germinate, keep the room temperature at a gentle heat of 55 to 59 degrees Fahrenheit. Once they've germinated, use a cool-white fluorescent grow light to aid their growth: place the light about 2" above the plants. Leave the light on 12-14 hours a day and be sure to raise it as the plants grow. Before transferring seedlings outdoors, harden them off by gradually acclimating them to outside conditions. To do this, place the seedlings outside during the day when temperatures are above 40 degrees Fahrenheit; do not set the plants in direct sun or high wind. Set them wherever there's shade. Move them out a bit more each day for greater exposure to the sun. Each night, bring the plants indoors. Provided they are at least 2" tall, after three to five days of hardening off, they'll be ready to transplant outside. STEP 4 Mark Rows Mark off the rows by staking the bed to create rows. First, place stakes the length of the bed and then stretch string along the ground to mark the planting line. Be sure to leave 20 to 36 inches between the rows for cultivation and plant at least four rows for the best pollination. Many short rows will provide better pollination than a few long ones. STEP 5 Form a Furrow in Soil Use the edge of a hoe to draw a shallow furrow, 1" to 2" deep, along one side of the string. You then remove the stakes and string and place ID markers at the end of the furrows. Drop the corn seeds into the planting furrows, spacing the seed drops 4" to 5" apart. Plant two or three seeds to ensure good germination. Cover the corn seed by raking 1-1/2" of soil over them using the soil from the edges of the furrow. STEP 6 Water and Protect Once the seeds are planted, water the block rows well. Good soil moisture is especially critical for the germination of extra sweet corn, as it must absorb more water than any other types for germination to occur. This crop will require at least an inch of water from rainfall or irrigation per week for normal growth. Now as the plants grow, there is some special care that needs to be given to the seedling. Mound the soil around the stems to support then against wind in exposed areas. When plants are about 6" tall, thin the seedlings. Crowded corn will bear fewer, smaller, and poorly filled ears. Using scissors, thin the plants to 8" to 10" apart if all seeds in a spot germinate and grow. Be sure to thin out the poorer seedlings, saving the best plant from each spot. This is also a good time to side dress the plants with 10-10-10 fertilizer, which will help encourage the young seedlings to grow. After you finish side dressing you lightly water in the fertilizer. Tip: As plants grow and weather becomes warmer, increase watering. When roots appear at the base of the stem, cover them with soil or mulch with old compost.