Trying to decide which sweet corn variety to plant by searching a seed catalog or looking over a seed rack can be very confusing. Many excellent varieties are available to home gardeners, and several new ones are introduced each year. Some factors to consider when you choose varieties are the kernel color, the maturity date, and disease resistance. Selecting a yellow or white kernelled corn is a matter of personal preference. Another choice is to plant a variety that produces bicolor ears, with both yellow and white kernels. Yellow corn has the nutritional advantage of being a fairly good source of Vitamin A. White corn contains virtually no vitamin A.
Sweet corn may be divided into four distinct types: standard, supersweet, sugary enhanced, and synergistic. Standard varieties contain a sugary gene responsible for the kernels sweetness and creamy texture.
Supersweet varieties contain a special gene that makes the kernels sweeter than those of standard varieties. Supersweet and sugary enhanced varieties convert the sugar to starch more slowly, preserving the sweetness for a longer time.
Kernels of the supersweet varieties have a crispy texture and contain low amounts of the water-soluble polysaccharides (complex sugars) that impart the creamy texture to other sweet corn varieties.
Synergistic varieties are numerous. Their cobs have one-fourth supersweet kernels and three-fourths standard kernels. Seeds of this type have the improved emergence characteristics of standard sweet corn.
Sweet corn requires warm soil for germination (above 55°F for standard varieties and about 65° F for supersweet varieties). These soil temperatures usually do not occur until late May, at the earliest, in our coastal area. Home gardeners can get a head start on corn germination by using special soil-warming protection such as polyethylene mulch film.
For a continuous supply of sweet corn throughout the summer, plant an early variety, a second early variety, and a main crop variety in the first planting. For example, you may wish to select Sundance (70 days to harvest) for the early variety, Miracle (85 days to harvest) for the second early variety and Jubilee (90 days to harvest) for the main crop variety. Make a second planting and successive plantings of your favorite main crop or late variety when three to four leaves have appeared on the seedlings in the previous planting.
Have you heard this? Plant cucumbers too close to watermelons and you will get a pink cucumber or a burpless watermelon.
Although plant oddities do pop up once in awhile, these are two you don’t need to worry about: cucumbers do not cross with watermelon, cantaloupe, pumpkin or squash, and potatoes will not cross with tomatoes.
However, if you plant different varieties of cucumbers, they will cross-pollinate, given the chance. If you don’t separate the varieties, any seed that is produced may not breed true, but could be a hybrid. There are some exceptions. It may seem strange, but summer squash such as zucchini and straight-neck will cross with pumpkin, but not with winter squash, and sweet corn will cross with field corn, changing both kernels and taste. It is important not to plant supersweet varieties near other varieties, since they will cross-pollinate and the result will be ears of corn with reduced sweetness.
Usually, you don’t need to worry about these fairly rare cases of garden cross-pollination, except in the case of corn. Even if your summer squash and pumpkins get together, the fruit will not be changed this year. However, you will notice the difference if you save and plant some of the seeds next year.