Corn Growing: Getting Started
Corn is a warm-weather vegetable that grows best during the long, sunny days of summer. The standard rule of thumb for seeding corn is to plant it two weeks before the last expected frost date. To extend your harvest a few weeks, stagger your corn plantings. This also prevents accidental cross-pollination of certain varieties.
Time your plantings by checking the days to maturity and counting back from the date you want to begin harvesting. One thing to remember is that the harvest time may vary slightly if the weather is very cool or very warm during the growing season. Timing your corn plantings is especially helpful if you're planning a midsummer vacation away from home. You needn't miss a single, delicious ear if you plan it right.
Soil and Site
Corn likes rich soil with good drainage. Ideal soil for corn is sandy loam that stays moist, without being too wet. The fastest way to improve less-than-perfect soil is to add plenty of organic matter (leaves, compost, grass clippings and crop residues). If your soil is too sandy, organic matter will help it retain nutrients and moisture, which are vital to corn. If you have heavy clay soil, organic matter will wedge between the soil's tightly compacted particles to loosen it and improve its drainage.
Corn has the same needs as most vegetables when it comes to soil pH (acidity or alkalinity). The best range for all vegetables is between 5.8 and 6.8 on the pH scale. This measurement indicates that soil is slightly acidic (the scale runs from 0 to 14, with 7 marking the neutral point). Anything below 7 is acid; anything above is considered alkaline. Contact your local extension service to have your soil tested every few years to be sure the pH is at an acceptable level. To raise or lower your soil's pH, you add lime or sulphur, and specific amounts are usually recommended in the test results.
As you're planning your garden, whether on paper or in your head, arrange the corn so it will be in at least four side-by-side rows to ensure good pollination. Be sure it gets full sun, away from trees that might shade it. Most corn varieties are tall and can shade shorter crops, so plant corn on the north or east side of the garden.
If you're growing corn for the first time, you may need to enlarge your existing garden. All you need to "sod bust" or turn a patch of lawn or an overgrown garden into a productive seedbed is a spade or tiller. Although it's best to break new ground the fall before you want to plant, you can create a new garden in the spring with fairly good results.
If you spade an area by hand, dig it to a depth of 8 to 10 inches and turn each spadeful of soil bottom-side up. This helps to keep grass from resprouting. Keep working the soil by chopping and stirring it, breaking up the clumps to make it loose and friable.
A tiller will also turn over sod to create a loose, friable seedbed. Till the soil back and forth until the seedbed is worked 8 to 10 inches deep.
If you've grown corn before in the same garden, change the place where you plant it, or rotate it, every year. This can be tricky if you don't have lots of garden space, but when you rotate corn, you prevent disease and pest problems from recurring. You also keep your garden's natural fertility in balance by moving heavy feeders, like corn, around. If your garden is too small for yearly rotation, rotate it at least every second or third season. If you run into a bad insect or disease problem one year, rotation the following season is a must.
Fertilizer -- A Fish Story?
Many gardeners have heard that colonists learned from the Indians to plant each corn kernel on top of a dead fish. This is no "fish story." Decaying fish contain nitrogen, which corn needs for good growth. The Indians and colonists may not have known why it worked, but they liked the results, so continued to do it.
Because it needs a steady supply of nitrogen throughout the growing season, corn is called a "heavy feeder." It's logical that a plant that can grow over six feet tall and produce hundreds of seeds needs lots of food. It's not so much the amount of food that matters as a steady diet while corn is growing. In fact, at planting time, corn needs about the same amount of fertilizer as most other garden vegetables. During the growing season, however, you give corn additional feedings by side-dressing the crop. There's quite a selection of fertilizers available today, and you should use whichever seems best for your garden and you.
Going along with the notion behind the dead fish of early American times, you can use an organic fertilizer such as well-rotted compost, aged or dehydrated animal manures or concentrated animal or plant extracts like bloodmeal or alfalfa meal. These materials may be available at little or no cost to gardeners in some areas. In other areas they may be prepackaged and sold at garden stores and the prices can be high. An advantage of these fertilizers is their ability to condition the soil as well as to feed plants. They also provide nutrients over an extended period of time, which helps corn. On the other hand, because their nutrient content may not be known, it's hard to judge exactly how much of some of these materials to use for best corn production.
Many gardeners use a balanced commercial fertilizer such as 10-10-10. The numbers indicate the percentages of nitrogen, phosphorus and potassium (N-P-K), and they're always listed in the same order on the label of each bag of fertilizer. Corn does best with high amounts of nitrogen, so pay special attention to the first number when selecting a commercial fertilizer. It should be equal to or higher than the other two elements listed. Chemical fertilizers are fairly inexpensive, and it's easy to use them in accurately measured amounts.
To achieve the best of both worlds, try combining equal parts of an organic fertilizer such as dehydrated chicken manure or compost and 10-10-10.
Broadcast or Sprinkler Method
You can apply fertilizer at planting time by "broadcasting" or sprinkling it evenly over a patch of soil, or by "banding" the fertilizer in the row where your seeds will be planted. Broadcasting makes sense if you want to fertilize a large area in a short time; you just sprinkle it on and work it into the top three to four inches of soil. Broadcasting also guarantees that fertilizer is available to every seed, although in smaller amounts than if you applied it in a band.
If you broadcast fertilizer, use 4 to 5 pounds per 100- square-feet of soil, or a 12-quart pail per 1,000-square- feet. Use about four times as much if you're broadcasting bulky organic matter.
Even though broadcasting fertilizer works well, banding it makes the most efficient use of the plant food. To band, sprinkle one to two cups of balanced commercial fertilizer down every 10 feet of row. Use about four times as much if you're using organic material, which has less concentrated amounts of the three key elements. Cover the fertilizer with an inch or two of soil before planting. Because corn is such an important crop in this country, there have been many studies to determine how to make the best use of fertilizers. As home gardeners, we can benefit from the results of this research.
It's been proved that the best place for fertilizer at planting time is in bands to the side and slightly below the seed. With this placement, the seed can't be burned by the nitrogen in the fertilizer, and the fertilizer is readily available in the soil by the time the taproot starts downward and side roots start to grow.
This article is a part of our Vegetable Gardening Guide for Sweet Corn / Getting Started.