There are several varieties of corn for the gardener to choose from; popcorn, dent corn, flint corn, pod corn, and sweet corn, just to name a few. Sweet corn is the most popular variety grown by home gardeners, though many also enjoy growing their own popcorn. Dent corn is the most commercially grown variety because of it’s many uses, it is used as livestock feed, ground into cornmeal or flour, has a high level of starch for producing corn starch, and many cosmetics are made with it’s byproducts.
Routine care is needed to grow corn organically, but will result in increased ear quality without the use of chemicals.
Choose a planting site that receives direct sunlight throughout the day and prepare the soil with plenty of organic matter such as well-aged manure or compost. Direct sow the corn seeds in the garden after the soil maintains a temperature of 50 degrees Fahrenheit or above.
Sow corn seeds 1 inch deep and 10 inches between each planting, plant in rows 3 feet apart. Water immediately after planting and once every 5 days until sprouts emerge. Reduce watering to once a week after that. Do not water on the weeks that receive more than 1 inch rainfall.
Place a nice layer of mulch over the soil around the plants to suppress weeds, add mulch as needed as it decomposes. Spread a 1/2 inch layer of well-aged manure or compost once a month to feed the corn.
Harvest sweet corn in the late fall about 20 days after silk emerges on the ears. Sweet corn that is ready to harvest will have brown, dry silk and green, moist husks. You can also puncture a kernel near the tip of the ear, if a milky liquid releases, the corn is ready to be picked.
Organic sweet corn will store in the refrigerator for 7 days with the husks left on. For the best taste use as soon as possible after harvest.
Corn Earworms and European Corn Borers can be a problem in your garden. Earworms cause of the worst damage as they attack the ears, or in other words the “fruits of your labor”. These can be controlled by applying diatomaceous earth or an organic insecticide spray to the silks when they are about 10% developed and continue weekly until the silks, or tassels, turn brown.
European Corn Borers infest the leaf and stalk, eating away at the stalk until it breaks, they also leave damaged areas that can allow pathogens to enter the plant and rot it. The best defense against these pests from invading is to use the parasitic wasp, Trichogramma. Trichogramma are commonly called the “stingless wasp”, the females inject their eggs into the eggs of pest insect. The larvae of the Trichogramma eat the embryo of the pest egg and emerge from the egg as adults ready to start the cycle over again.