Corn Can Be a Sweet Choice for the Home Gardener

by 
Ron Kushner, for the Shuttle

Corn (Zea mays) is truly an American native, cultivated for more than 4,000 years by many civilizations. Sweet corn is the home-garden favorite, either white, yellow or bicolor. To me, fresh corn on the cob is the essence of summer (along with a fresh-picked ripe tomato).

You don’t need a huge amount of space to grow corn. A 4-foot-by-4-foot raised bed will easily handle 16 stalks. Plant three different sections, if possible: End of May, mid June and July 4th. This succession planting will give you fresh corn well into the fall, as you can usually depend upon two ears per stalk.

Corn is a cold-sensitive crop and should not be planted until at least two weeks after the last frost date, May 15 in our area. The soil should be 60 degrees F. before planting seed. It will not germinate at lower temperatures and could easily rot if spring weather is wet and cool. Seed should be planted directly in the garden, as seedlings don’t adapt well to being transplanted. Seed generally lasts two years if kept in a cool, dry place.

Grow corn in full sun. It is a heavy feeder, especially on nitrogen, and likes a rich, well-drained soil. It is a good idea to enrich the soil the previous fall with lots of compost and if possible, a cover crop of beans, alfalfa or clover. Cut down the cover crop, turn under and mulch before a hard freeze. In the spring, remove the mulch to allow the soil to warm up faster and apply more compost before planting.

Corn should be planted in blocks rather than rows, with seeds about a foot apart in all directions so that there is no need to thin the plants later. This spacing will also promote complete pollination. In an early planting, sow seeds 1 inch deep. Later plantings in hot weather should be deeper, 2 to 3 inches. If you are planting different cultivars, you must keep them at least 400 yards apart to avoid cross-pollination.

You can cover seeds with floating row covers supported by hoops to maintain soil temperature and protect seeds and seedlings from frost and birds. The cover can be removed once night temperatures are above 60 degrees. 

Control weeds by mulching well. The soil should be kept evenly moist but not wet. The plants should never dry out and should be watered especially well when tassels, which are the pollen-bearing male flowers, begin to appear. Water around the base of the stalks so as not to wash away the pollen — drip irrigation is an excellent way to insure adequate moisture. 

Fertilize with a granular fertilizer when stalks are about 6 inches tall and again when tassels begin to show. If using liquid fish fertilizer, fertilize weekly for the first month. Don’t remove any side shoots or suckers. They won’t affect production and you could damage the shallow root system. 

In order to produce kernels, wind must deposit pollen from the tassels onto each of the silks on the ears. Every unpollinated silk results in an undeveloped kernel. When ears begin to show, check leaves for holes and ears for tunnels through them, which are signs of the corn earworm. This insect is an inch or two long and striped in yellow, green or brown. If the pest is showing, spray mineral oil, vegetable oil or neem oil on the tip of each ear. The oil will drown the worms. Make sure to apply the oil only after the silks wilt and start to turn brown. This indicates that pollination occurred. You can also spray Bt (Bacillus thuringiensis).

Harvest the corn when the silks are brown and damp at the very ends and the kernels feel plump and tender. To confirm an ear is ready to harvest, pull back the husk just enough to press a kernel with your thumbnail. If a milky liquid squirts out, it is ready. To harvest, twist the cob off the stalk. Pick corn in the early morning, when the sugar content is at its highest, then refrigerate in the husk until ready to eat.

After harvesting corn, chop up the stalks for faster composting. The smaller the pieces, the faster they break down.


For questions or comments: ron@primexgardencenter.com