This document printed from the University
of Illinois Extension Garden Column at http://www.extension.uiuc.edu/williamson/
Time to Plant Sweet Corn
April 29, 2008
Ed Billingsley
County Extension Director, Williamson County and Interim County Extension Director, Jackson County
Williamson County Unit 1306 N Atchison Ave, Ste A
Marion, IL 62959
Phone: 618-993-3304
FAX: 618-997-1542 edb@illinois.edu
Mary an avid column reader called and asked me to write about sweet corn.
Sweet corn is a very popular crop and it usually can be found in most home gardens.
This crop is wind pollinated but one can see bees working the tassels as well. Because of this it is best to plant several short rows rather than one long row to improve pollination.
When planting sweet corn it is best to wait until soil temperatures reach 60˚F at a 2 inch soil depth before planting. Sweet corn seed should be planted 8 to 9 inches apart in the row and 1 to 2 inches deep depending on available moisture.
Today we have white, yellow or bicolor sweet corn types with different levels of sugar content. Bicolor varieties have 20% white kernels and 80% yellow kernels. There are standard (SU-1), sugar enhanced (SE), Supersweet (SH2) and synergistic (SY) types of sweet corn based on sugar content.
An SE has higher sugar content with tender kernels these are a great choice for homeowners. Supersweets (SH2) are bred for longer shelf life but have tougher kernels. Supersweets have poor germination and should never be planted in cool soils.
Sweet corn should be isolated; to prevent cross pollination. Planting different types 150-250 feet apart will reduce cross pollination. One can also stagger planting every 14 days to prevent this.
Sweet corn strives on nitrogen so apply nitrogen at planting. An appication of a complete fertilizer sometimes is best suited for sweet corn such as 12-12-12. One would apply 9 pounds of this fertilizer per 1000 square feet of row. An additional application of 5 pounds per 1000 square feet should be side dressed along the row when the corn reaches 6 inches in height. Additional nitrogen fertilizer such as 34-0-0 may be added if corn appears off color.
Early planting of sweet corn helps prevent insect damage. Mineral oil mixed with Bacillus Thuringiensis can control corn earworm if applied to the silks two days after silk emergences.
Some varieties one should consider include "Incredible" a yellow SE," Delectable" a bi-color SE or "Saturn" a yellow SH2.
Sweet corn should be refrigerated immediately after harvest. Harvest should be done in early morning while temperatures are cooler. Sweet corn has a shelf life of 4 to 6 days for maximum flavor. Sweet corn should be eaten or processed before that.
Sweet corn is an excellent way to sweeten your vegetable plate. So consider it for your garden.
