Weather conditions are generally acceptable to start planting corn in Kentucky by April 1. Current research and farm data suggest that corn planting can start at the end of March and go through June 1. Coffee shop talk suggests that several (or more than several) acres were planted in March this year. 

Generally, the conditions are more important than the calendar. Soil moisture below field capacity and soil temperatures at or above 50 F for 3 to 4 days with a good forecast are good conditions for corn planting. However, if corn planting occurs at warmer temperatures, corn will germinate more quickly, and often, more uniformly. For example, if the average daily temperatures are 50F and 65F, then corn will take about 15 days to emerge. If average daily temperatures are 55F and 80F, then corn will take about 6 or 7 days to emerge. 

Uniform seeding depth is critical to uniform corn emergence. Seeding depths of 1.5 to 2 inches are ideal in most silt loam soils of Kentucky. In the sand lenses along some of the major rivers, seeds can be as deep as 3 inches. If seed is placed shallower than 1.5 inches, the plants may not anchor properly and could lodge later. Shallow seed placement usually results in visual potassium deficiency when corn plants are about V4 to V6. 

While seed monitors do an excellent job of tracking seed spacing nothing fully replaces visually inspecting seed depth behind the planter and making certain that closing wheels are working properly.

Since spring is Kentucky usually follows a roller coaster of air temperatures and rain events, if soil conditions become risky for planting corn, switch to soybeans. Soybeans are less sensitive to early-season stress and less sensitive to large shifts in final plant populations. 

References

University of Kentucky Cooperative Extension Service. ID‑139: A Comprehensive Guide to Corn Management in Kentucky. Revised December 13, 2022.

Chad Lee, chad.lee@uky.edu