How Long After You Plant Corn Should You See it Break the Surface?

Time

• Corn seedlings need 100 to 125 growing degree days (heat units calculated based on the daily temperature) to emerge, according to the Purdue University Extension. In warm soils, emergence can take as few as five to seven days, while cold soil emergence can require four weeks to occur.

Temperature

• Corn requires soil temperatures of at least 50 degrees F and sufficient water and light for germination to occur. The Iowa State University Agronomy Extension suggests that corn needs a constant soil temperature of 86 degrees F for optimal emergence.

Influencing Factors

• Emergence may be negatively affected by cool soil temperatures, cold temperature stress, soil surface crusting, saturated and compacted soils, seeds being planted too deeply, and blight, according to the Purdue University Extension. The extension further warns that chilling injury -- from absorption of and exposure to cold rain and melting snow -- delays emergence and can kill seedlings.