Corn plants need plenty of space because they are large and must also be planted in blocks of rows at least four across so the wind can scatter their pollen to neighboring plants.
In areas where the soil stays cool longer, cover it the ground with black plastic or IRT film a week or two before planting and set transplants through holes cut into the material.
The tassels appear at the top of the corn plant provide the pollen that drops to the ears below and causes the tasty kernels inside to fill out. You must have good tasseling and pollination to have good corn.
Corn plants may produce suckers at the base called tillers. If they appear, just leave them.
Corn is ready to harvest when the silks are brown and the ear is filled out. Peel back the tip of the ear to check the sap.
Sometimes the tip of the ears or kernels even deep down in the ear don't fill out.Sinking your teeth into a perfectly ripened ear of sweet corn is one of the finest pleasures of summer, and early-maturing sweet corn varieties like Sugar Buns will offer a harvest sooner than you might think. You will need to wait three weeks longer for Silver Queen, but your reward will be kernels packed with sweetness and rich corn flavor. The sugars in old-fashioned Pencil Cob Corn rapidly turn to starch, so they can be roasted when fresh, or the dried kernels can be ground into meal. Colorful ears of Indian Corn never taste sweet, but after you finish using them in seasonal decorations, they can be parched in hot oil or ground into a coarse meal suitable for using as rustic polenta.
Corn needs plenty of space for two reasons -- it is a heavy feeder, and it is primarily pollinated by wind. As grains of pollen are shed by the tassels that grow from the plants' tops, they must find their way to the delicate strands of silk that emerge from newly formed ears. To make sure silks are nicely showered with pollen, grow corn in blocks of short rows rather than a long, single row. In a small garden, fifteen plants set one foot apart can be grown in a 3x5-foot bed. Growing corn on this tiny scale is a good way to introduce yourself to the crop if you’ve never grown it. After the first year you will probably want to increase the size of the planting to at least 4 rows 10 feet long.
Corn plants are not like tomatoes and most other vegetables that bear over a long period of time. Instead they form a few ears per stalk and they are finished. Because of this, gardeners who have the space often make two or three plantings two weeks apart to keep the harvest coming.
Soil, Planting and Care
Corn needs a spot with that gets full sun and has fertile, well-drained soil with a pH of 6.0 to 6.8. Seedlings can be set out as soon as the last spring frost has passed. Space transplants of larger growing varieties such as Silver Queen 8 to 12 inches apart; of smaller types such as Pencil Cob 6 to 8 inches apart; our tags will say. In case of a surprise late frost, be prepared to cover seedlings with a fabric row cover.
In cold climates you can plant in a raised bed covered with black or IRT plastic (infrared transmitting plastic) that will warm the soil. If possible, lay the plastic a week or so before planting.
Plan to fertilize twice because corn is a hungry plant. Before setting out seedlings, amend the soil with compost and mix a balanced organic or timed-release fertilizer into the soil. About a cup 10-10-10 per 10 feet of row is a good general rate, but trump that with the rates given on the label of any fertilizer you are using. About six weeks or so later, when the plants start to produce tassels, fertilize them again. (If you amend the soil with cottonseed meal or other high nitrogen amendment, it may not necessary to feed the second time.) Use a hoe or trowel to mix the fertilizer into the top inch of soil between the plants. After this booster feeding, water your corn weekly if the weather is hot and dry.
Normal plants should grow fast with dark green healthy leaves. Corn will tell you if it is hungry by turning very light green. If so, feed again.
Corn grows fast and needs lots of water to grow properly. It also has shallow roots that make it susceptible to drought. Soaker hoses will insure that your corn gets the water it needs. However, for a large planting, soaker hoses may not be practical, in which case you will need a sprinkler or two with a large coverage area.
Hopi and Navaho Techniques
Native Americans in arid climates planted corn in basins to catch spring rainwater and help keep the corn roots down where water would be available longer. The basin was about 4 inches deep and 2 to 3 feet wide with a raised ridge made from the excavated soil around it. Plants were arranged so that they formed a spiral from the center to help with support in wind and with pollination. If you live in an arid climate or a hot climate and have poor sandy soil such as the Coastal Plain, this technique could help insure a good harvest.
Harvesting and Storage
Most corn plants will yield at least two ears per stalk. Hybrids may yield more.
It can be hard to know when an ear of corn is ready to harvest because you can’t see inside the husk. Look at the silks. They should be brown and dry with just a little fresh green at the base. Squeeze the husk to see if the ear inside feels plump, not skinny. If the ear seems ripe, check by peeling just enough of the husk back to expose a couple inches of the ear. Poke a kernel with your fingernail. The corn is ready to pick if it bleeds a light milky sap like skim milk. If the liquid is clear, the ear is not ready. Ears that are too ripe will look too milky, like cream vs. skim milk; they often taste starchy. Of course, remove them, too.
Perfectly ripened ears also taste sugary-sweet when sampled raw. When possible, harvest sweet corn in the morning, when the ears are cool. To remove the ear, use one hand to hold the corn stalk and the other to pull the ear down and away from the stalk, twisting a little until it breaks off.
Place harvested ears in the refrigerator right away. When kept chilled, ears of Sugar Buns will hold their sweet flavor for up to a week. Extra sweet corn can be blanched and frozen, on or off the cob.
Allow ears of grain corn to stay on the plants until the husks dry to tan. Gather them during a period of dry weather, and pull back the husks before using the ears as seasonal decorations. Remove all husks before storing dried ears for the winter in a cool, dry place.
Troubleshooting
Corn plants that are blown over by gusty storms usually right themselves after a few days of sunny weather. Pop off ear tips damaged by corn earworms as you shuck and clean your corn.
The different types of corn should not be allowed to cross-pollinate. That means that standard hybrid types such as Silver Queen, open pollinated types such as Indian Corn and Pencil Cob, and super sweet types need to be planted in such a way that pollen from one type does not reach another type. Everlasting Heritage (EH) types such as Sugar Buns don’t need isolation. If you or a nearby neighbor grow multiple types, be sure that they are isolated by at least 250 feet or their timing is such they are not in bloom at the same time. If not, the pollen from types that are not the same can muddy their characteristics to the point of ruining sweetness and flavor.
Raccoons love corn. The most effective way to keep them out of the patch is to surround it with a fence with two stands of electric wire 4 and 12 inches from the ground. Some gardeners have been successful with throwing black bird netting over and around the plants because some raccoons don’t like it. The methods from keeping raccoons out of corn are as varied as gardeners themselves. We’ve heard of people putting flashing lights in the corn patch, putting a radio on a timer to blare loud music, laying newspaper in rows because the raccoons don’t like to walk on the crinkly paper, spraying animal repellents, and other techniques, but a physical barrier such as an electrified fence seems to be the most reliable.