Wondering how to grow corn in a raised bed, or even just a small garden space, with maximum yields of delicious corn? I'll show you the whole simple process, step by step, in this thorough guide to planting, pollinating, and harvesting corn properly. You can't fail.
In This Article
- How to grow corn in a raised bed
- How to plant and grow a corn patch in your garden space directly in the ground
- Considerations for square foot gardeners
- How to hand-pollinate corn
- Three sisters planting
Native to the Americas, where it has been cultivated for many thousands of years; corn is delicious. It's famous as one of the "Three Sisters" —corn, beans, and squash—grown by Native Americans.
This year I'm growing an interesting type of heritage flour corn or flint corn called Painted Mountain Corn in two of my raised beds. My raised garden beds are each 5x5 feet with an arched trellis between them that will be used to support squash and pole beans — yes I'm using a layout variety of the traditional Three Sisters planting method.
Home gardeners can plant any type of corn (like delicious sweet corn) in your own raised bed or garden plot and you don't have to use the Three Sisters method but we'll cover all of that in depth in this guide.
Can You Start Corn Seeds Indoors?
Yes, technically you can start corn seeds indoors two weeks before transplanting but there is really no need to rush. And it is best to direct sow due to the nature of corn's delicate and shallow root system.
I actually do know people who have successfully started corn indoors and then transplanted it outside, but their yields were not as great as when they started it outdoors directly.
So keep all that in mind.
The best way is to start corn outside through direct sowing after all danger of frost has passed. It does not tolerate cool soils, although some varieties have been bred to be hardier.
How To Grow Corn In A Raised Bed
Corn can easily be grown in a raised bed or in the ground. The instructions and method will be the same.
One of the top benefits of raised bed gardening will be your ability to control weeds and maximize soil quality, type, and nutrition.
The advantages of a raised bed is that they offer better drainage, are easier for controlling weeds and some pests, and the soil quality is likely much higher while also not being compacted.
And raised bed for corn should be 12 inches (a foot) but a minimum of 6 inches (if your soil is good) can be used to successfully grow corn. But more doesn't hurt either. I grow in 17-inch raised beds.
And keep in mind that corn is a tall plant.
Whether you are growing in raised beds or in the ground, one of the most important factors o remember is that corn should be planted in blocks to achieve maximum pollination and thus maximum yields.
Plant Corn In Blocks For Good Pollination
My 5x5 raised garden beds are a perfect square and will ensure the greatest pollination success. If you're planting in the ground directly, you should still be planting in blocks.
Do not plant your corn in long rows. You will not get healthy yields, or any yields at all.
More on pollination below.
How To Plant Corn Step-By-Step
First, make sure you're planting after any and all danger of frost has passed. Corn does not tolerate cold soil so do not be impatient.
When is my last frost date?
Select your site. Corn stalks are tall so make sure they do not shade out any other plant in the garden. You want at least some protection from strong winds if possible. Corn also requires well-drained soil.
Make sure you're planting into warm soil. The best time to plant is when soil temperatures are 85 to 90 Fahrenheit.
- Block off a square in your garden that has full sun exposure and rich soil high in nitrogen. This can either be a patch of ground in your planting area (free from any grass or weeds) or a square raised bed. As mentioned, I'm using a square 5x5 raised garden bed that is 17 inches tall.
- Do not soak your corn seed before planting.
- Water your bed thoroughly before planting.
- Plant your corn seeds. Sow 2 corn seeds seeds 1 inch to 1 ½ inches deep in the same hole, 12 inches (1 foot) apart. Square foot intensive gardeners sow 4 seeds per square foot evenly spaced apart (see below for more specifics).
- Water thoroughly again. Corn needs plenty of water during germination and then after the tassels and silks emerge. Water as necessary, 1" per week.
- Corn needs 7-10 days to germinate and you should keep the soil surface damp.
- Thinning: Once your seedlings are about 4 inches tall, thin to 1 seed per 1 square foot. Square foot gardeners, do not thin seedlings unless you planted more than 4 per square foot. Make sure to cut the extra seedling off below the ground as the corn plant can actually grow back.
- After thinning you should have 1 corn seedling per square foot, or 4 corn seedlings per square foot depending on your growing method.
- Be careful with your plant's delicate, shallow root system which can be easily damaged by careless weeding or rough handling.
- Your corn will be ready to harvest depending on the variety you have planted. This varies wildly from 65 days and up to 110. Check your seed packet and make a note of planting and sprouting times.
Corn is actually a type of grass. All grasses are pollinated by the wind.
Corn tassels, which are loaded with the pollen necessary for growing cobs, will emerge from the top of the plant right before the long silks come out (see picture above) and each strand of silk is actually a potential future KERNEL of corn! But to develop into a kernel, it must be pollinated.
Poor pollination results in poor yields, no yields, or "skips" in the ear of corn where kernels are missing as the silk was never pollinated.
Once silks have emerged and the tassels have opened and are dropping pollen, shake the plants to improve pollination and decrease any chances of skips.
You can also hand-pollinate you corn by cutting off a tassel and wiping it on the silks so that the pollen makes really thorough contact with the silks.
One tassel can be used to pollinate up to 10 ears of corn this way.
Square Foot Garden Corn Planting
Do not attempt square foot gardening on a whim as you're likely to see poor yields.
You need to do it properly for success, and a specific soil mixture is a huge part of that, and it carries very specific instructions.
Get the square foot gardening book or read up about it online.
Square foot gardeners are intensive planters that aim to maximize each square foot of space.
Each plant has its own rules of planting density, and for corn you can plant 4 seeds per square foot.
It's up to you if you choose to plant 2 seeds per hole and then thin or just go with one.
Use something like a traditional twine or wooden lattice grid laid overtop of your bed to ensure proper spacing, or just do what I do and get a seeding square. It's one of the most beneficial tools I have.
If you grow a variety of corn that yields two cobs per corn plant, you can really get a big harvest although the extent of your yields may very well vary in such an intensively planted bed.
Staggered Planting For Continuous Harvests
This is more important for those of you growing sweet corn varieties.
You can plant another row (add it to your block) every two weeks, and thus extend your harvest by staggering it. This way you don't suddenly have to harvest dozens of ears of corn that need to be eaten quickly.
But if you're planning on freezing, canning, and fermenting, this may not apply to you.
And if you're growing corn for drying into flour, do not stagger your planting.
Corn must be planted in an area where it gets full sun exposure.
It needs a minimum of 6 hours daily.
Corn needs plenty of water, at least an inch of water weekly.
Consider soaker hoses or drip irrigation for convenience.
Soil & Fertility
Corn is a heavy feeder, especially of nitrogen, which is why a three sisters layout (see below) can be an ideal way to corn corn by companion planting it with nitrogen-fixing plants.
The best way is to use plenty of organic mater like compost.
Our soil is incredibly fertile but as this will be my first year with these new raised beds and new soil I will be adding a heavy layer of compost, and then an additional feeding of organic nitrogen fertilizer (slow release blood meal) at planting time.
Weed your corn garden bed periodically to keep them from competeing with your corn for nutrients and water.
I strongly believe in mulching for soil health, weed suppression, and water retention.
You can mulch your corn with a variety of materials but I prefer chopped straw, the same type we use in our chicken coops for bedding.
Choose The Type Of Corn To Grow
Any variety of corn can be grown in a raised bed or small garden plot and there are five types of corn, here is a brief overview of each:
Sweet corn is one of the two types of corn most people are looking to grow, with flour corn being the second. Sweet corn is, well, sweet and sugary and delicious. And the variety you grow yourself will be better tasting than anything you can buy. Actually, if you can pick and eat your corn within 10 minutes it is reported to be the best flavor-wise.
Flour corn is meant to be dried and then ground into flour.
I chose flour corn to grow this year because it is difficult to find organic masa harina here and I want to try my hand at drying and nixtamalizing it myself. It's also one of my top crops in a survival garden.
Flint corn is also known as "Indian corn." It is very hard and comes in many beautiful colors. It is grown for livestock feed, ornamental use, as well as for making into flour. Popcorn is a type of flint corn.
It's called dent corn because of the little dents on the kernel. This corn is hard, but not as hard as flint corn. It is used for livestock feed and as an ingredient in many commercial foods. Dent corn can be used to make corn meal.
Not something you're likely to come across or grow yourself, or even want to. Called tunicate maize, there is a husk covering each kernel.
Three Sisters Corn Layout In Raised Bed
Here is a quick phot of my raised bed garden plans.
Raised beds #1 and #2 (at the back) is where our corn is being planted.
Between the raised beds are tall arched trellises where we will be growing food like squash and beans vertically.
Those two beds are examples of a three sisters layout, an indigenous method that goes back centuries.
The genius of the method is that it pairs nitrogen-fixing plants like squash and beans with corn which is a very heavy nitrogen-hungry plant.
I will be planting bush beans on the outer edges of the corn.
Then on the trellis I will be growing pole beans, winter squash, and summer squash.
There are many different three sisters layouts you can use in your space.
Our Raised Beds
After lots of research, we have made a decision — these are the raised beds we will be installing in Spring of 2023. Follow me along on Instagram or right here on the blog for all the designing and planning and planting.
Common Corn Pests & Diseases
Corn Earworm aka European Corn Borer
The European Corn Borer, or corn earworm (see the photo above) which is also known as a tomato fruitworm is one of the most destructive pests across North America.
Adult corn earworms are actually tan-colored moths that then lay round, white eggs on corn silks and underneath the leaves.
The larvae are 1"–2" long caterpillars, light yellow, green, pink, or brown with white and dark stripes along sides. The larvae will feed ravenously on the ear tips of sweet corn and the pods of green beans, burrow into ripe tomatoes and peppers, and feed on a wide range of other plants.
There are several ways to control the corn earworm. One of the best is to attract beneficial insects that like to eat them, their eggs, and the larvae: lacewings, ladybugs, and several parasitic flies and wasps by panting pollen and nectar plants like Sweet alyssum with your corn.
Regularly inspect your developing corn for signs of the pest and act accordingly.
Best Companion Plants
What To Avoid Planting With Corn
More Grow Guides
Intercropping With Corn
Once your corn plants are about 4-6 inches tall, you can direct sow beans to grow in between the stalks if you like.
They will grow in perfect harmony and you will get the most yield from your beds.
Growing Different Varieties Simultaneously
YES you can grow two different varieties of corn — provided that you plant them two weeks apart.
This is crucial to avoid cross-pollination.
Conversely, you can keep your corn beds 300 feet apart.
There is a massive range of dates between corn varieties so make sure you know when you can expect to start harvesting your corn.
Sweet Corn Types
Sweet corn is ready to harvest around 3 weeks after the silks first start to appear. You should harvest when the silks are brown, but not dried out, and the husks are a dark green. The ears should be plump and rounded at the tip, not pointed.
To test the ripeness of the corn, just pull back the husk and pop a kernel with your nail. The liquid should be whitish; and if it is still running clear, ears are not quite ready.
Once you have picked your corn you should enjoy as soon as possible. The sugars quickly convert to starch which alters the flavor and sweetness. Many people attest that sweet corn should be cooked within 10 minutes of picking.
For dry corns used for flours and popcorn or cornmeal, you let the ears dry directly on the stalks. See the photo above for reference.
Flour corn types are ready for harvest when the kernels are hard and you can no longer leave a mark on them when you press in with your nail.
Time the harvest before the first fall frost and pick all of your corn by giving each ear a twist until it breaks off. Peel back the husks, then hang the ears in a cool, dark, dry place for 4 to 6 weeks to cure. This step is crucial to prevent mold.
To strip off cured kernels, twist the cobs back and forth to loosen them. This can be painstaking and a little hard to do, you should really wear gloves to make it easier on your hands.
Some people will also chop the entire corn stock and hang it somewhere dry to finish drying and curing.
Hopefully this thorough guide has answered your question on how to grow corn in a raised bed garden or directly in the ground. If not, feel free to ask questions in the comments below.
Corn is a relatively easy crop to grow and there are countless varieties to choose from. Whether you prefer a super sweet sugar variety or want to make masa harina like I do — go ahead and plant a corn patch.
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