When home gardeners first invite 'Ruby Queen' sweet corn into the vegetable patch, it's almost certainly for the novelty of its claret-colored kernels. And why not? Red table corn isn't exactly a grocery-store staple. But gardeners from Maine to California have discovered that this striking sugar-enhanced (SE) hybrid is a keeper: tender, tasty, productive, and vigorous. 'Ruby Queen' holds its color when cooked, staging a coup de rouge in a corn relish or black-bean salad. Corn provides thiamin (vitamin B1), pantothenic acid (vitamin B5), folate, dietary fiber, phosphorus, and manganese. A large (8-inch) ear of corn has approximately 123 calories.
Corn has simple needs: It wants only the best. Given ample warmth, sun, water, fertilizer, and room to grow, corn is a surprisingly reliable crop. 'Ruby Queen', like all SE hybrids, possesses a naturally occurring gene that produces sweeter, more tender ears with a longer peak of condition than oldfashioned varieties. To maintain quality, SE hybrids should be grown at least 300 feet from field corn, popcorn, ornamental corn, and supersweet hybrids.
Full sun and rich, compost-amended soil are key to corn cultivation. Protection from prevailing winds will prevent these shallow-rooted plants from being blown over in summer storms.
Sow seed at least 2 weeks after the average last-frost date at a soil temperature of
55°F or higher. Sowings may be made up to 3 weeks earlier if the soil has been warmed with a clear plastic or infrared-transmitting (IRT) plastic mulch for at least a week. Because corn is wind pollinated, it should be grown in four or more side-byside rows or in blocks, rather than one long row. Work 6 pounds of complete organic fertilizer beneath each 100 linear feet of row. In traditional beds, place rows 2 feet apart, with three or four seeds clustered every 8 inches and sown 2 inches deep. Thin to the strongest seedling per cluster. For more-intensive block culture, set plants 15 inches apart in all directions in deep, fertile raised beds.
Beds may be covered in floating row cover to retain heat and protect emerging shoots from crows and voles; remove cover when seedlings are 4 inches tall. To extend the harvest, make additional sowings at 2-week intervals, or plant an early and a late variety to round out midseason 'Ruby Queen'. Presprouting is helpful in cool-spring areas. Corn does not transplant well unless started in biodegradable pots that can be placed directly into the soil.
Keep corn well watered at the roots (watering overhead when the pollen is flying can reduce ear-fill). Fertilize every 2 to 3 weeks with fish emulsion until plants begin to tassel, or side-dress twice with a high-nitrogen fertilizer, once when plants are a foot tall and again before silk appears. Weed frequently.A mulch of grass clippings or compost will retain moisture and reduce weeds.
The 8-inch ears of 'Ruby Queen' ripen about 3 weeks after silk appears. Although prime eating quality persists over a 5-day period, flavor is best just as the color approaches full ruby ripeness. Pick ears immediately before cooking or in the very early morning and refrigerate (34°F) in the husk until needed. Don't forget to save the ornamental, 7-foot crimson stalks for autumn decor.
In the home garden, controlling corn earworm (Helicoverpa zea) can be as simple as placing a clothespin where the silk enters the ear as soon as silk emerges. Or, once the silk wilts and turns brown, suffocate the worms by applying five drops of corn or soybean oil into the tip of each ear. If the caterpillars do appear at ear tips, hand-crush or remove the pests and reseal husks with a twist tie.
Presprouting Sweet Corn
In cool soil, corn may rot rather than germinate. Once seeds have broken dormancy, however, they will continue to grow in less-than-optimal soil temperatures. Presprouting turns this tendency to the gardener's advantage, adding several weeks to the start of the growing season. To presprout, spread corn seed in a single layer between wet paper towels. Roll up and place in an unsealed plastic bag. Keep warm (70° to 80°F). Check daily and do not allow the toweling to dry out. Plant seed at the first sign of a root, which should appear beneath the seed coat in 2 to 4 days. Be careful when handling germinated corn: The longer the root, the more easily it can be damaged.
'Ruby Queen' holds its blush even in boiling water; many cooks, however, prefer to steam, microwave, or grill it, husks removed or not, to retain the full depth of color. Do not overcook—garden-fresh corn takes only 3 minutes in unsalted, boiling water. To freeze, cut kernels from cooked ears. Or, for an out-of-season, on-the-cob treat, freeze uncooked ears in the husks—silks removed—sealed in plastic bags. In season, the ruby-hued morsels complement a bounty of sun-ripened fare including cucumbers, tomatoes, onions, peppers, zucchini, garlic, cilantro, and basil. Mix and match, and finish by tossing with olive oil and fresh lemon juice.