Corn doesn't need any more attention than other garden vegetables, but it's a crop that can take up a fair amount of time if you plant a lot. Make it easier by combining tasks. For instance, when you side-dress, pull any weeds you see, or side-dress at the same time you hill the rows.
Like any plant, corn produces better if it doesn't have to compete with weeds. It's especially important to keep weeds out when corn plants are young. Once the stems and leaves are established, they can tolerate weeds better. Plus, the stems and leaves of larger corn plants shade the soil somewhat to block out weeds.
Weed your corn every few weeks, starting before you even plant a seed. Work the soil several times before planting. This not only conditions the soil, it stirs up and kills tiny weed seeds lurking near the surface. It also buries some seeds so deeply that they never get a chance to sprout.
Once the corn is planted, scratch the surface of the planting bed every week or so with a weeding rake. When the corn is tall enough to be hilled, you'll automatically get rid of weeds by covering them with soil as you hill.
Hilling is pulling up soil to mound it around the base of a plant. When you hill a young corn plant, the added soil around its stem helps support it as it grows taller. This protects it from being blown over in a strong wind. To really anchor plants, it's a good idea to hill corn every two to three weeks until the plants start to tassel.
Hilling also covers and smothers any weeds around the base of your corn plants. You might say you're creating a "soil mulch" around your plants. If dryness is a problem, extra soil helps the corn roots retain moisture.
You can hill with a hoe by scooping a few inches of soil from the walkways into loose mounds on both sides of the corn. If you want, you can hill your corn by machine, using a tiller with a special hilling attachment. This is both faster and easier than using a hoe, and it also does a uniform job.
The more you feed corn, the more it will feed you, so side-dressing (a second dose of fertilizer that boosts growth) is a must with corn.
You can use any high-nitrogen fertilizer to side-dress corn, because nitrogen is the plant nutrient needed. A commercial fertilizer such as 10-10-10 works well, but you can also use well-composted or dehydrated manure, or commercial organic fertilizers like cottonseed meal.
Side-dress corn twice: when it's knee high and when it tassels. To side-dress, sprinkle a thin line of fertilizer or manure about four inches from the plants on both sides of each row of corn. To side-dress hill-planted corn, simply sprinkle fertilizer around each hill, about four inches away from the cornstalks. It often helps to make a shallow furrow first for either rows or hills. The furrow serves as a guide and the indentation helps the fertilizer stay put.
If you side-dress shortly before it rains, you're lucky. Otherwise, you should water, so the fertilizer leaches into the soil where it can be taken up by the corn roots.
Corn doesn't need more water than other vegetables. It just suffers more if the supply runs short. The plants are relatively tall and exposed to the wind and drying heat of summer, so they often "transpire" or give off moisture faster than their roots can take it up.
Corn's need for water is most critical from the time it tassels until the ears are ready for harvest. At this time, the plant is devoting all its energy to seed production, holding nothing in reserve for a dry spell.
During its growing season, corn needs at least an inch of water per week. If it has to go through a dry stretch, it may not produce well. Use a rain gauge to keep track of weekly rainfall. If your garden receives less than an inch of rain in a week, water.
When you water, water thoroughly. If you're using an overhead sprinkler, use your rain gauge to determine how long it takes to deliver an inch of water. Or, simply water until the soil feels moist three to five inches down, depending on your soil type. (Sandy soil absorbs water faster than clay.) One sign of too little water is the corn leaves curling or rolling. If you want healthy, sweet, well-filled ears, pay close attention to the weather at the tail end of the season and water if your corn needs it.
If you have the equipment, it's most efficient to water corn with a soaker or drip irrigation hose, or to use furrow irrigation. A soaker hose is made of a material such as perforated canvas that lets water seep out slowly. Drip irrigation has lines running straight to each plant that constantly drip a small amount of water to the roots. If you water directly from a hose or bucket into a furrow, it accomplishes the same beneficial watering at the base of the plant. With these watering methods, less water is lost to evaporation than if you use an overhead sprinkler. The water doesn't end up on the leaves of tall corn plants, instead it's near the roots where it's really needed.