Corn Growing Guide

Corn on the cob has long been a staple on dinner tables and farms across the country. It’s an art that has been perfected by both commercial growers and home gardeners for as far back as we can remember. Corn is probably one of the most versatile vegetables on the planet and exists, in some form or another, in just about everything we do. From ethanol to glue to soda, corn has staked its claim as the #1 crop in most parts of the world but we love it most as an extremely reliable and sustainable food source.

Where did corn originate?
Corn, as we know it today, has come a long way from its humble beginnings. It is thought to have been derived from a wild grass called teosinte in Mexico around 10,000 years ago. The very small cobs had only a few kernels surrounded by a hard casing. Over the centuries, as it has spread across the globe, corn has been domesticated and by the 15th century, was a major European food source.

Where is the best place to grow corn in the U.S.?
While corn can be grown in most parts of the United States, the part of the country known as “The Corn Belt” is one of the most fertile places on earth to grow corn. Over 10 billion bushels of corn a year come from the Midwestern states of Indiana, Illinois, Iowa, Missouri, eastern Nebraska, and eastern Kansas. Corn thrives in this area of the country because the region is flat, the soil is very deep and rich in important nutrients like nitrogen. Corn is a summer crop and loves the hot days and warm nights of the Midwest. 

Can I grow corn in raised beds and containers? 
We have been growing corn here at HOSS for a very long time. So while you may see plenty of information on the internet that might suggest otherwise, growing corn in raised beds and containers is not something we recommend. Corn is pollinated by the wind, not insects, so in order to have a good, healthy crop, you need to be able to plant a minimum of 5 rows of corn to get proper pollination between the plants. From a space standpoint, corn is just not well suited for raised beds and containers.

The 4 Major Types Of Corn

Here in South Georgia and most of the world, sweet corn reigns supreme in our gardens as an excellent food source but there are other types of corn that are very useful too. One major benefit of growing corn is that despite your choice of variety, in most cases, corn has the same requirements for growing but gets harvested and stored slightly differently from type to type. This helps make fertilization, irrigation, and planning much easier from year to year. So when choosing a corn variety, it’s helpful to know the different types based on your intended use. The 4 types of corn typically be broken down into 4 categories; popcorn, sweet corn, flint corn, and dent corn.
While some varieties only fit into one of these categories, for example, Honey Select Sweet Corn only falls into the category of sweet corn, Glass Gem Corn is a popcorn as well as a flint corn. 

As the name suggests, popcorn is the type of corn that has hard, shiny kernels that when heated will burst. Popcorn needs to be dried in the husk in the garden for as long as possible.

Sweet corn is normally what you see in grocery stores and dinner tables. With its high sugar content, sweet corn is harvested at the "milk" stage and the kernels stay tender and juicy when cooked.

Flint corn, commonly known as Indian corn, has hard, dry kernels and is mainly used to make animal feed, grits, and flour. Very ornamental and some varieties can also be used as popcorn.

Dent corn is known as such because of the small indentations in the kernel's crowns. It has a high starch content and is grown to use as ethanol, sweetener, grain, animal feed, grits, flour, etc.

Planting corn for the first time can be tricky if you’re not familiar with how corn pollinates. Corn is not pollinated by insects like other some vegetables and instead uses the wind to carry the pollen to fertilize the plants and produce kernels on the cobs. Unlike other vegetables that can easily be planted in one long row, corn should be planted in blocks of at least 5 rows. Planting in one or two long rows will likely just blow the pollen off of the plants and you will end up with blank spots or cobs with no kernels.
Isolation is another major factor in planting corn. Because corn is pollinated by the wind, you shouldn’t plant different varieties within at least 300 feet of each other to keep the plants from cross-pollinating. 

Each variety of corn has different quantities per pound based on the type of corn you’re growing. Also, the seed spacing and row spacing differ between field and popcorn vs. sweet corn. Be sure and check each product page for how many seeds per pound are included with that particular variety of corn to make sure you’re purchasing the right amount of seed for your space.

Field Corn & Popcorn
Based on 8” seed spacing with 36” row spacing and 5 extra seeds per row to be on the safe side.
20 seeds/10 ft. row 
60 seeds/10’x10′ Plot (3 rows)
600 seeds/1000 sq. ft.
This means you would need roughly 29,000 seeds of field corn or popcorn per acre.

Sweet Corn
Based on 6” seed spacing with 36” row spacing and 5 extra seeds per row to be on the safe side.
25 seeds/10 ft. row 
75 seeds/10’x10′ Plot (3 rows)
750 seeds/1000 sq. ft.
This means you would need roughly 32,000 seeds of sweet corn per acre.

Row Spacing – 30 to 36 inches
Plant Spacing – 6 inches
Planting Depth  – 1 inch
When choosing a spot to plant your corn, make sure it has full sun and won’t be shaded by other plants. Using the HOSS Garden Seeder makes planting corn using the right spacing much faster and easier. 

Hilling Corn Plants

As your corn grows, they will need special maintenance throughout the season. Every 2-3 weeks, they are going to need extra support by mounding up dirt loosely around the base. This process is called hilling and is really vital in the growth cycle and root development. Hilling helps greatly with weed suppression, plant support, and preventing suckering that will stunt development.
Using the Hoss High Arch Wheel Hoe or Double Wheel Hoe with the plow attachments oriented for hilling to make quick work of getting your plants properly hilled. Once the plants get to around 18 inches, hilling is no longer necessary.

We always recommend using a drip tape irrigation system to grow corn for several reasons.
1. Corn has high water requirements during pollination and during final ear filling. Drip irrigation ensures the plants are getting the right amount of water directly to the root system during these vital times.
2. Corn can become stressed in heavy droughts and improper irrigation during dry periods can increase this stress. Drip irrigation ensures each plant is getting the required amount of moisture.
3. Drip irrigation helps to keep weed pressure down while seedlings are starting to emerge.
Overall, the rule of thumb when you grow corn is thatcorn plants require 1″ – 5″ of water per week while they are growing and only need around 2″ per week once the corn starts to tassel.Depending on your zone, if you have more rain during the summer, be sure and account for extra moisture in your irrigation schedule.

Sweet corn is harvested in its immature stage so that the sugars contained in the corn don’t have a chance to turn into starch. This stage is called the “milk stage” because of the milky white fluid in the kernels. A good test to see if your harvest is ready is to push your thumbnail into a kernel and see the color of the fluid. If it comes out watery and clear, it’s not quite time yet. If the liquid is slightly see–through and has a milky appearance, that’s what you’re looking for. However, if you puncture the kernel and the liquid that comes out is thick and not see-through, you’ve likely waited too long to harvest. But hands down the easiest and, in our opinion, the best method is to just check the silk on the ears. As long as all of the silk has turned brown and there is no green present, your sweet corn is likely ready to harvest. We’ve found that sweet corn is at its very best when harvested early in the morning. Simply twist and pull the ear off of the stalk. Depending on the variety of peas you are growing, harvesting is relatively simple. Simply use two fingers to pick the pea from the vine, being very careful not to damage the vine itself. Harvesting often will signal the plant the continue to produce more peas and get several harvests. To shell your field peas, simply break them open at the “seam” and dump out the peas into a container.

Once your sweet corn is picked, the clock starts on how quickly you will lose that signature sweetness. If you don’t plan on eating your freshly harvested sweet corn within a day or two, we highly recommend preserving it somehow. The longer the fresh cobs are off the stalk, the less sweet the kernels will be and they’ll become starchy and closer to what you might find in a grocery store instead of that amazing fresh taste you get from homegrown corn. If you’re planning on freezing your sweet corn, a good idea is to take it off of the cobs beforehand to maximize your storage space in your freezer. Keep your sweet corn in their husks and sealed in a plastic bag in the refrigerator until you’re ready to eat fresh.

Unlike sweet corn that is picked while immature, popcorn, dent corn, and flint corn have to dry out and cure completely on the stalk before harvesting. In order for these harder kernels to be ground into cornmeal, popped for popcorn, or shelled, the moisture content has to be a certain level. While this may not be an issue for commercial farmers with the right equipment, it may prove to be more difficult for the home gardener to determine the specific moisture content of a cob of corn. These varieties should be left in their husks on the stalks for as long as possible until the stalks and leaves are totally brown and crunchy. After you see this happening, you can test the corn to see if the kernels easily come off of the cobs. If they do, chances are your corn is ready to harvest and the moisture content is accurate. 

Popcorn can be left on the cob or shelled depending on your preference and storage space. For popcorn to pop, the moisture content needs to be between 14% and 18%. Again, without proper equipment, it can be difficult to tell if it’s just right. Luckily, popcorn has a very easy test you can perform. Simply remove several kernels from the cob and pop them using a microwave or an air popper. If most of the kernels pop, you’re good to go. If not, let them keep drying and keep testing. If you are using your corn solely for ornamental purposes, you can leave the husk on the corn and string them up to continue to dry out even further. We recommend giving your ornamental corn a coat of varnish to not only make it shiny and make the colors pop but to also keep potential pests at bay.