In the Garden
Amy Jordan, Special to The Gazette
Originally published 01:25 p.m., May 8, 2008
Updated 01:25 p.m., May 8, 2008
Sweet corn is a popular summer vegetable planted by many home gardeners.
Choosing a variety of sweet corn to plant has become complicated because of the advances in breeding and genetics.
The following information on sweet corn varieties, derived from the K-State Research and Extension Horticulture Newsletter by Ward Upham, Extension Horticulturist, will shed some light on the differences among the types of sweet corn commonly available to homeowners.
Standard (su): This is our “normal” sweet corn and contains a “sugary gene” (su). Standard sweet corn should be isolated from field corn, popcorn, supersweets and ornamental corn. To isolate one type of corn from another, do not plant one type within 200 to 250 feet or have a difference of 12 to 14 days in time to maturity. Plant when the soil temperature reaches at least 55 degrees. Recommended varieties include Honey and Cream, Silver Queen, Sterling Silver, Jubilee or Merit.
Supersweet (sh2): Though supersweets have up to 3 times the sweetness of standard sweet corns and hold their sweetness longer after harvest due to the sh2 gene, they do have some drawbacks, such as tougher kernels and a lack of some of that good “corn” flavor. They also need to be isolated from other sweet corn types and are very sensitive to cooler soils. Wait until the soil temperature reaches 65 degrees before planting. Try Candy Store, Florida Staysweet, Sugar Loaf, Sweet Time or Sweetie.
Sugar Enhanced (se): These are probably the most popular type of sweet corn grown due to their tender kernels, good flavor and less sensitivity to cool soils (60 degree soil temperature for planting). They hold their post-harvest sweetness longer than standard types but will not hold sweetness as long as the supersweets. The sweetness from the sugar-enhanced types is due to the “se gene.” If both parents were se types, the variety is known as an se+ or se se. If only one parent was an se type and the other an su type, then the variety will be listed as se. They do not need to be isolated other than from the supersweets. Suggested varieties include Bodacious, Ambrosia, Sweet Temptation, Delectable and Miracle.
Triplesweet (synergistic): The newest types of sweet corns blend the su, se and supersweet types with the goal of combining the best characteristics of each. We don’t have firm recommendations yet but you may want to try Serendipity, Polka, Avalon or Frisky.
Sweet corn requires wind to transfer pollen from the tassel (male) to the ear (female). Plant corn in small blocks or several short rows rather than a single row to encourage better pollination. Sweet corn pollinates poorly in 100+ F weather and ears with missing kernels or gaps may result.
Sweet corn may be cross pollinated by other types of corn such as field corn that pollinates at the same time. If there is a danger of cross pollination, a space of 40-50 feet may be needed, as cross pollination can affect flavor.
Sweet corn is a member of the grass family and needs considerably more nitrogen fertilizer than other garden plants. A bit of additional fertilizer sprinkled along the row every several weeks is important.
Sweet corn needs regular watering as well because its sparse inefficient root system does not reach to deep soil water. Apply 1-1 1/2 inches of water per week. Weed control is necessary, especially in young plantings.