A long time ago it was an easy choice as to how far apart to plant corn rows. People planted the rows the amount of space needed for farm animals to pull a plow through. For us gardeners there is still some practicality to this kind of thinking as we need the rows spaced at least far apart enough to walk through for fertilizer application and pest control.
Proper spacing and corn seed depth at planting are essential for good growth and yields. After looking at advice from gardeners and farmers alike the best way to space corn in a garden is every 3″ along a row and then thinned out 6 to 8 inches apart in a row with rows spaced 2 feet apart. Corn seeds should be planted 1.5-2 inches deep.
Thin the plants out when they are 4-6 inches tall by leaving the better growers and pulling out the smaller plants. Corn planted closer than 6″ apart will increase competition for light, water, and nutrients which will lead to stress and poor stalk quality.
Twin row planting is done by some farmers. It involves having double rows spaced 30″ or 38″ apart. The row of double rows are spaced 7.5″ apart and staggered so that a plant from one row falls in the middle of two plants from the other row forming uniform triangular spacing.
Corn is pollinated by the wind so you want to have more of a rectangle or square shaped grouping with more rows that are shorter as opposed to one or two long rows. If pollination isn’t successful we end up with no ears or a corn cob that is missing patches of kernels. If you’re growing different varieties and want to avoid cross pollination the best way to do this is to place bags over the ears before silks appear and to hand pollinate.
Hilling or twin row planting are two other methods. Hilling is similar to the method above and involves having a raised mound about a foot in diameter with 2-3 corn plants in it and the mounds spaced 2-3 feet apart. An alternative to hilling is mounded rows, where you mound up dirt to make a raised row and then plant in the mounded row.
A mounded row is the best method in my opinion for most plants in the garden. Planting in a row you get a higher plant density than planting in mounds. The mounded row has the benefits of the mound, better drainage and increased soil temperature, and the benefits of the row.
How Do Farmers Plant Corn?
Farmers typically plant rows 20 or 30 inches apart. There is a debate to which method gets more yield with variety chosen and weather of the season all playing their part in yield results.
Farmers aim for 24,000-38,000 corn plants per acre depending on the field’s yield potential and the planting date. It’s common practice to over plant seeds by 5 to 10%. Planting date is a factor because seedlings will have better germination rates later in the spring than early spring when the soil and air temperatures are still cool.
Corn farmers start with the same choice as us gardeners, what variety of seed to grow? If weather allows for early planting, a variety that has a longer date to maturity can be chosen and vice versa if the weather doesn’t warm up until later a variety that matures quicker will be chosen. Also for farmers that choose rows 20″ apart they may like a certain variety over another because they feel it does well with less space.
Farmers use a piece of equipment called a planter that is pulled along by a tractor. Planters come in different sizes from 2 rows to 50 rows. Seeders or grain drills are similar pieces of equipment but used for smaller seeds like wheat and other cereals. The planter allows the farmer to set the seed rate and planting depth for the rows.
Most planters will have bulk storage containers for seed and fertilizer and be able to dispense a small amount of starter fertilizer along with every seed. More modern planters use GPS and auto-steer systems on the tractors that allow for precise planting. On uneven fields where the tractor has to make passes over already planted soil these automatic systems will withhold dropping seeds until it is back on unplanted land.
How to Plant Corn By Hand
Planting corn by hand is done the same way most planting by hand is done. Use a tool to make a straight line where your row of corn is going to be. Then go back along the line and use your finger to make a hole 1.5-2 inches deep every 3 inches. You can plant the corn seed as you go or go back to plant the seed. Then cover with dirt, pat lightly, and water.
Planting Corn In Hills
Planting corn in hills involves making hills about a foot in diameter and spacing hills along a row 2-3 feet apart. Plant 4-5 seeds 3″ apart in a hill and thin down to 2-3 plants per hill when appropriate. Rows of hills are spaced 2 feet apart.
Planting in hills can increase soil temperature and drainage but in my experience planting in hills leads to less successful germination and lower yields than planting in a straight row. You can mound a row and get the same benefits of increased soil temperature and better draining.
Corn Plant Spacing In Raised Beds
Remember that we want the corn to be planted in a block as opposed to a long row so aim for at least four rows of corn. Plant 2 or 3 seeds 1.5-2 inches deep and 12″ apart in all directions. Thin down to one plant per spot by cutting the smaller plants off at the base. Were aiming for 1 corn plant per square foot. Don’t pull them out by hand to avoid bothering the roots of the corn plant you want to leave.
Corn Seed Spacing In A Pot
Growing corn in a pot can be done but it’s better if you have enough space to do multiple pots so that you can have a block of corn and ensure pollination. If pollination doesn’t occur you’ll end up with no cobs at all or cobs that are sparsely filled with kernels. Hand pollination is a good idea if growing corn in pots.
Have pots that are at least 12″ deep. Plant 2 or 3 seeds in the same spot 1.5-2 inches deep and 8″ apart from each other. If you are using a 5 gallon container you can do three corn plants per container in a triangle formation. Thin down to one plant per spot by cutting the smaller plants off at the base. With pots aim for about 1.5 corn plants per square foot.
Does Corn Flower?
Corn does “flower” but it does not put out what we normally call flowers. Corn plants are monoecious, meaning that one plant puts off both male and female flowers.
The male flowers are the tassels on the top of the corn stalks. When they mature they shed tiny pieces of pollen that get spread by the wind. Female corn flowers are the silk that protrude from the ears. Each individual piece of silk will become a kernel if it is pollinated.
You can help corn pollination out by manually pollinating ears. You want to hand pollinate when the weather is dry. You can take a few tassels off of the tops of the corn plants and place them in a bag and shake it up. Take pinches of the pollen and spread it on the silks. You can pull back the husk some to expose more of the silks. Do not take all the tassels at once and repeat the process every day for a week.