Growing corn can be a sweet new gardening adventure | Home/Garden

Sweet corn harvested fresh from the home garden and cooked soon afterward is one of life’s great treats. If you have never had that experience, now is the time to plant sweet corn in the garden.

Sweet corn plants are large, and they occupy a good amount of space. As a result, many vegetable gardeners don’t plant corn. Each plant produces only about two ears of corn, so overall production is not as high as it would be for other popular vegetables like tomatoes, squash, peppers or trellised cucumbers. But if you have room, growing sweet corn is fairly easy and the results are delicious.

Types to grow

Corn is harvested over a relatively short period as all of the ears ripen at about the same time. If you have room, you can extend the harvest season by planting seeds every two to three weeks through April. You may also plant early, midseason and late-season varieties.

There are several different types of sweet corn. Standard sugary sweet corn varieties like Merit (yellow), Silver Queen (white), and Sweet G90 (bicolor) differ from field or grain corn in that kernels produce more sugar and less starch. They are also creamier.

A disadvantage of sugary corn is that while it’s sweet at the time of picking, it loses its sweetness quickly after harvest as sugar is converted into starch. That’s why homegrown sweet corn cooked shortly after harvest is so sweet and delicious.

Sugary-enhanced sweet corn varieties have higher sugar levels. Even though sugar is still converted into starch after harvest, sugary-enhanced varieties have a higher sugar content for a longer time than regular sugary varieties do. Sugary-enhanced varieties include Ambrosia (bicolor), Argent (white), Avalon (white), Bodacious (yellow), Incredible (yellow), Miracle (yellow), Precious Gem (bicolor) and Temptation (bicolor).

Supersweet sweet corn varieties have very high sugar levels, and this sugar is not converted to starch as quickly after harvest as it is in sugary and sugary-enhanced corn. However, supersweet corn has a less creamy texture. Supersweet varieties include Cameo (bicolor), Honey N’ Pearl (bicolor) and Ice Queen (white). There are also some varieties that combine two or all of these genotypes. Honey Select (yellow) is one example.

While all types of sweet corn should be grown away from field corn and popcorn, supersweet varieties also need to be at least 200 or 300 feet away from other types of sweet corn to maintain maximum sweetness. Another way to isolate corn types from one another is to plant them at least 14 days apart.

Planting

Planting corn early — now through mid-April — reduces problems with corn earworms, the leading insect pest of corn in the home garden. Generally, when planted this month, corn may not require any pesticide sprays at all.

To prepare the ground for planting corn, first remove any weeds or unwanted vegetation, then turn the soil to a depth of a shovel blade (about 8 inches). Apply a 2- to 3-inch layer of compost or composted manure and a general-purpose fertilizer following package directions, and thoroughly mix everything together.

Plant two or three seeds every 10 inches in the row, burying them about one-half to 1 inch deep, and water in thoroughly. The rows should be at least 2 to 3 feet apart. After the seeds germinate and the plants are three to four inches tall, thin to one plant per 10 inches.

Sidedress sweet corn plants with a nitrogen-containing fertilizer (calcium nitrate, ammonium sulfate) when the plants are about 16 inches high and again when the plants are about 36 inches high. Corn benefits from generous fertilization.

Pollination issues

Corn is wind pollinated. The male flowers that shed the pollen are located at the top of the plant in the tassel. The female flowers are arranged in rows along the cob enclosed by the shucks. Each silk is connected to a female flower. At least one pollen grain must land on each silk to pollinate a female flower. Each kernel of corn is the result of a separate act of pollination, so it is important to plant corn properly to make sure the wind deposits the pollen on the silks.

For that reason, we plant sweet corn in a block planting of several short rows side by side rather than one or two long rows. By planting in blocks, you allow the pollen to move from one plant to another more surely no matter which way the wind is blowing. Ears that are poorly filled with kernels of corn are generally the result of poor pollination.

Some gardeners take this further and do hand pollination. When the tassels at the top of the plants begin to shed the yellow, powdery pollen, tassels are cut and shaken over the silks of each ear.

Harvest

The best time to harvest sweet corn is in the early morning when the temperature is low to retain sweetness. To determine when sweet corn is ready to harvest, first check the silks to see if they have turned brown and dry. Then feel the ear. It should feel firm and full.

Peel back a shuck enough to puncture a few kernels on the ears with your thumbnail. When sugary and sugary-enhanced sweet corn is at its highest quality, the juice from the kernels will be milky white and runny. For supersweet varieties, the juice will be clear and watery. Sweet corn is over-mature and starchy when the juice inside the kernels is thick and doughlike.

Corn usually matures 18-24 days after the tassels appear, or 15-20 days after the first silks appear. Refrigerate or cook immediately after harvesting.