Growing Sweet Corn - Rules For Growing Super Sweet Types
Since its introduction more than 20 years ago, the Super Sweet corn varieties have become favorites of sweet corn consumers. At farmers markets you constantly hear the question “Is this variety super sweet?” or vendors’ signs displaying their varieties as “Super Sweet”. The crisp, juicy kernels, big ears and superb holding qualities of Super Sweets have won the hearts (and tastebuds) of sweet corn lovers everywhere.
Following are some basic rules that must be followed when growing Super Sweet varieties successfully.
1/ ISOLATE. Cross pollination between Super Sweets and other corns (including field corn) will result in a starchy, undesirable kernel in both. Plant Super Sweet varieties at least 25 feet from other corns in the garden and 200 feet from varieties in acreage plantings. However, you can plant more than one Super Sweet variety side by side. You can also isolate by planting time, allowing at least a 10-day difference between either your planting date or the maturity date of the corn variety.
2/ SOIL TEMPERATURE MUST BE WARM. Super Sweet seed that has been treated with a fungicide should not be planted until the soil temperature is at least 60 degrees F. and after danger of frost is past. If the Super Sweet seed is untreated, soil temperatures should be a minimum of 70 to 75 degrees F.
3/ PLANTING TIPS. Super Sweet corn seed is smaller than normal sweet corn seed and there are many more kernels per pound. If using a planter, set it for the proper seed size and planting depth (3/4” to 1”), spacing seed 8 to 12 inches apart in rows 2 to 3 feet apart. To improve pollination, we recommend planting a block with multiple shorter rows rather than one or two long rows.
4/ KEEP MOIST. Super Sweet seed requires more moisture than normal corns. Avoid dry soil planting.
5/ FERTILIZE AND CULTIVATE. Super Sweets have the same high fertilizer requirements as normal corns. Apply a balanced fertilizer to your soil before planting or use a high-phosphate starter in your planter. Keep weeds away during the growing season and the soil cultivated shallowly.
6/ HARVEST TIPS. Upon tasseling, watch for and record the date when about half the plants show silk. Your corn will be ready to pick about 18 to 22 days after this date depending on temperatures during this period. If temperatures are very warm, maturity will be earlier. The corn is ready to pick when the kernels are full. Because Super Sweets hold their tenderness and sweetness longer than other varieties, picking can be done over a longer period of time.
7/ REFRIGERATE. Super Sweets have about twice as much sugar content at harvest compared to other sweet corns and become even sweeter after picking. This is due to a slower sugar-to-starch conversion. For best quality, refrigerate after harvest to keep it fresh as long as possible.