When to Plant Corn in Missouri?

You may be starting to think about planting corn in Missouri. It’s not too early to get your seed and soil fertility programs ready for a successful crop of feed and/or silage corn, wheat, cotton or soybeans. Let’s look at when to plant corn in Missouri?

Corn is grown on more acres than any other row crop in the world with strong demand from all areas of agriculture. From the feed trough to the fuel tank, corn has many uses.

It is estimated that around 1 acre of corn is grown for every person in the United States with over 90 million acres harvested each year—that’s about 40% of all row crop production in this country. Many factors go into planning for a good corn crop including weather, price, commodity programs, grain storage and more.

Studies on When to Plant Corn in Missouri

when to plant corn in Missouri? 

The best time to plant corn in Missouri is in April or May. Corn planted earlier in the year may not reach its full yield potential because of poor pollination caused by periods of hot, dry weather during July and August.

University of MO

Scientists at the University of Missouri have found that planting corn on Tuesday gives optimum results throughout much of Missouri. The study was conducted by testing various planting dates in Columbia, Missouri. Planting dates included Tuesday, May 20; Thursday, April 24; and Saturday, March 28.

The scientists found that planting on Tuesday gave the highest yield of any day tested throughout much of Missouri. However, this study may not be accurate for areas north of Interstate 70 or areas south of Interstate 44.

Planting later than May 20 may result in fewer pollinating days during the growing season, which decreases yield potential.

Monsanto Study

However, studies conducted by Monsanto indicate that yields are not severely affected when planting is delayed until June 6 for Missouri locations north of Interstate 70 or until June 18 south of Interstate 70 or along the Mississippi River.

These studies suggest that planting corn after June 6 (north of Interstate 70) or June 18 (south of Interstate 70 or along the Mississippi River) will not result in a yield penalty.

When to plant corn in Missouri? Guide

Here’s the best practices for planting and growing corn in Missouri

when to plant corn in Missouri? 


The ideal planting time for corn is when soil temperature at a 4-inch depth is above 55 degrees Fahrenheit or mid-May in southern Missouri and 60 degrees F in northern Missouri. This way the corn crop will be off to a good start, but planting dates can vary with crops like soybean and cotton.


Corn is grown in more than half of Missouri’s counties, but production depends on optimal growing conditions. The best soils are deep, fertile, well-drained loams that hold moisture during dry periods.

Know Your USDA Hardiness Zone

Hardiness zones in Missouri range from 4a in the Bootheel to 6b in northern counties near the Iowa border. Warm season crops like corn and soybeans grow best in zones 5-6.

Corn Spacing

Corn can be planted into standing or very shallow-tilled residue that remains after wheat, rice or sorghum harvest. Leaving residue on the surface protects the soil from erosion and helps to conserve moisture.

Farmers can plant corn with a planter or drill (used for no-till systems). Row widths vary, but 30 inches is common in Missouri. A final stand population of about 35,000 plants per acre will provide good competition against weeds and insects. With fewer plants per acre, plants will require more space between them to develop a good root system and the crop will be more susceptible to drought.


If you plant corn from seed treated with a fungicide, start scouting for diseases when plants are knee-high. Most foliar diseases develop after flowering begins and can cause severe yield loss if not controlled. Keep in mind that planting date and moisture conditions can play a large role in disease development.


Maintain proper fertility throughout the life of the crop to maximize yield and quality. Nitrogen is important for stalk and foliage growth and should be applied around planting time or sidedressed during June and July if low in the soil.


Apply 50 to 75 pounds per acre of nitrogen as a starter. In conventional tillage, band 50 pounds of nitrogen per acre in a 6-inch band near the planter or drill shank. In no-till systems, apply all nitrogen in a 12- to 20-inch band over the row at planting time. Use a high analysis fertilizer such as 15-0-15 and adjust the rate to soil test levels.

Corn hybrids vary in their response to nitrogen application, so it’s important to select a hybrid adapted for your area and manage fertility accordingly. Plant populations also affect corn yield. Increasing the seeding rate by 10% will increase yield up to a point, but increasing seeding rates beyond 35,000 plants per acre will not increase yield.

You may also be interested in: 8 Grasses that are Native to Missouri

Phosphorus and Potassium

when to plant corn in Missouri? 

The best time to apply phosphorus and potassium is before planting, but these nutrients can also be applied in starter fertilizer if no manure was used the previous year. Phosphate-solubilizing bacteria (PSB) inoculant can boost corn yields by 6 to 10%. PSB colonizes plants roots and makes phosphorus available to the plant. Corn hybrids vary in their response to PSB, so stick with a product that fits your hybrid.

Fetilizer Placement and Timing

Nitrogen source, placement and timing are important factors when applying fertilizer. Urea or anhydrous ammonia can be used for sidedressing, but make sure these products are thoroughly incorporated into the soil before planting. Apply urea or anhydrous ammonia in a 6- to 8-inch band over the row and incorporate with a toolbar, spike tooth harrow or similar tool. Application of nitrogen fertilizer (urea or anhydrous ammonia) too shallow can lead to plant injury.

Ammonium sulfate should be applied in split applications around planting time and again at midseason. Use ammonium sulfate on corn hybrids that are highly sensitive to nitrogen source, such as Agrisure Artesian. Corn hybrids vary in their response to sulfur application. In general, apply 0-20 pounds of sulfur per acre if the soil test is low and 10-30 pounds of sulfur per acre if the soil test is high.


Apply micronutrients at planting with the phosphate-solubilizing bacteria, but don’t apply zinc or copper unless soil levels are low. Soil testing is important because most soils contain adequate levels of these nutrients. If needed, apply zinc at 0.75 pounds per acre and copper at 1 pound per acre in a starter fertilizer.

When to plant corn in Missouri? :Conclusion

Hopefully this article has helped you determine when you should plant your corn in Missouri. Good luck!