Sweet corn is an annual crop that produces ears of yellow, white, or bi-colored kernels. A long, frost-free growing season is necessary for growing corn. Here’s how to plant, grow, and harvest corn in your home garden!
About Corn
Corn (maize) is one of the Three Sisters—corn, beans, and squash—and has been in cultivation for thousands of years. Native to North America, corn is thought to have first been domesticated in central Mexico, spreading from there through different peoples across North and South America. Today, corn is grown on an industrial scale, but there are quite a few varieties that are well suited to growing in home gardens, too.
A member of the grass family (Poaceae), corn relies on wind to pollinate its flowers, so it should be planted in blocks of short rows instead of long, single rows.
Types of Sweet Corn
Corn comes in early-, mid-, and late-season varieties. Early-season varieties are the quickest to mature, while late-season may take the entire growing season. For an extended harvest, plant varieties with different “days to maturity.”
There are four main types of hybrid sweet corn: sugary (su), sugar-enhanced (se), shrunken (sh, sh2), and synergistic (sy). Each one contains a different level of sucrose, changing the flavor and texture of the corn. Sweeter varieties will also stay sweeter for longer after harvest. Read more about the differences between these types in the Recommended Varieties section below.
Reader Comments
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Great article
Thanks for the excellent growing tips for corn. I live in zone 7a and was surprised to see the planting times. I realize it's a guide but would stress to others that average soil temps should determine actual planting dates. I rarely plant corn before mid may. Last year with the sugar enhanced variety it was May 28th, which according to my log is the latest planting in 30 years of growing corn.
Starting earlier when the soil is cooler than optimal has no advantage and may have the opposite effect when the weather is cool and wetter than normal. Thanks again.
Sweet Corn Farming
The basic information provided on sweet corn its verities and farming is enlightened indeed.
Thank you from Solomon Islands South Pacific Ocean.
Corn
My corn has extra large kernels. Wondering why?
kernel size
Good question! We looked into a few educational resources and while few explain kernel size directly, they emphasize ear size on which, of course, the kernels form. So, from Purdue University:
Optimum growing conditions set the stage for maximum ear size potential and exceptional grain yields at harvest time.
(and) Kernel number (ear length) is strongly affected by environmental stresses. This means that potential ear length will vary dramatically from year to year as growing conditions vary. Severe stress can greatly reduce potential kernel number per row. Conversely, excellent growing conditions can encourage unusually high potential kernel number.
See more here https://www.agry.purdue.edu/ext/corn/news/timeless/EarSize.html
Hope this helps—
Brown tassels
When you say brown....could that mean dark maroon? Or is my corn Almost ready for harvest? It's be 83 days. The cobs don't appear to be very big. I'm in zone 8a and my stalks are in a raised garden bed.
Starting corn
On the coast of Maine, it is quite common for people to start corn indoors. Mine are usually 4-6 inches tall when I put them in the garden and they never skip a beat. I use an open pollinated golden bantam called Ashworth. It has a lovely corn flavor but needs to be cooked immediately as the sugar gets starchy quickly.
Aflatoxin
As a first time corn grower "dent/flint" for use as corn meal. Why is aflatoxin not mentioned in this article.
aflatoxin
We simply don’t know everything! Thank you for bringing this to our attention. Aflatoxin is a naturally occuring fungus that appears on many types of organic material, including grains, nuts, and decaying vegetation. Certain conditions, usually high heat and high humidity cause it to thrive. You can read more here https://extension2.missouri.edu/g4155 and here https://www.douglas.k-state.edu/docs/cropsandlivestock/cropsandlivestock-library/Aflatoxin_Iowa_State.pdf
Overwintering corn?
My husband and I have grown corn for over 5 years now, and we always miss a few ears of corn that end up overwintering in our garden. Without fail, each year in the springtime, the corn kernels on the ears of corn that overwintered begin to grow plants of their own. The plants begin growing much earlier than what we would normally plant our own corn, and the plants seem to be much healthier (thicker stalks, greener leaves, etc.). My question is this: Have you ever heard of farmers planting corn kernels in the late fall/early winter for a crop the following summer? Given what you know of corn, do you think there is merit to planting in this manner?
Growing zone
I forgot to mention - we live in Growing zone 3-4 (right on the border of the two zones).
Too Late for this Year?
Hi! I live in the Shenandoah Valley, I think my zone is 6b. I wanted to direct sow some corn weeks ago, but of course things came up and I waited and now I feel like it may be too late. The variety I have is Ashworth, and it says on the packet it takes 69 days. Does that mean that if I plant it tomorrow, I'd have corn by August 4? Or just a decent-sized plant? Or is it too late to plant them? My grandma used to say that when the oak leaves are as big as a squirrel's ear, that's when you plant your corn...the squirrels would have very large dumbo ears at this point in time. Secondary question: I have black walnut trees around my house, and I think corn is supposed to be resistant to the toxin they produce. But would I be better off planting in containers? Thanks for the help!
Planting Corn
Generally, you’d want to plant corn between mid-April and mid-May, depending on how the weather is in spring. The soil should be warmed to around 60°F, in any case. The days to maturity is just that: the days it takes for the plant to reach maturity and start producing. If you start it now, you should expect harvestable corn by the end of August. So, in your case, it’s not too late to plant, and you may even be able to sneak in a second harvest before frost if you plant another round of seeds in a week or so. (Find your frost dates here.)
As for your second question, you are correct: corn is resistant to juglone, the toxic substance produced by black walnut trees. Feel free to plant it in the ground!
Pollination
I've planted corn a few times, here and there, and had not luck. Last year, I tried again after doing some research. As the article mentions, corn is wind pollinated and I don't have enough space to plant in large blocks. It is necessary to pollinate by hand. To do this, carefully slip a small paper bag over the tassels and secure with a binder clip or some such thing. Leave over night. The next day, carefully remove the bag, so as not to spill the pollen that has accumulated, inside. Using an artists brush, transfer the pollen to the silk of each ear. Do this when the ears begin to form and silk has appeared.
pollination bagger
Everyone has their methods, but as you mentioned, corn is wind pollinated and in my honest opinion bagging and painting pollen is not necessary and a complete waste of time. All one needs to do in Billyboy Baggins case is walk/reach into your corn patch and shake the darn things, which is precisely what the wind does. Best of luck!
Volunteer corn and beans
I recently put St. Augustine sod in an small area of yard behind my house that is fenced off from our dogs. About a week after laying the sod I noticed three corn stalks beginning to grow as well as three bean sprouts along the border on each side of the sod. Two of the corn stalks are right up next to a concrete block and the other right next to some large rocks I have bordering grape vines. The corn stalks are about eight to ten inches tall now and I'm wondering if I should try to move them to a place where they will have more room to grow. I would like to see if they actually produce corn but don't want to damage them. Do you have any suggestions?
Corn
You can transplant at that stage. Better before now - so protect it from the sun and water well.
You must live a lot further
You must live a lot further south than do I!
Concerning yard lights and the effects it may have on my garden
It's May of 2018 and we just moved into a new house. I'm very determined to have a vegetable garden this year as I have always been raised to have one but new environments present new problems. My neighbor has a giant yard light on the pole that sits directly between our back yards as well as one in the front near our street. The red lighting covers every inch of my property and I was just wondering will the lighting have any kind of effect on my corn, tomatoes, cucumbers, and speckled beans? The spot where I plan on putting my rows will be roughly 50 to 60 ft away from the source of light. Any feedback will be much appreciated thanks.
Red Lights
Don’t fret! It’s unlikely that the light is strong enough to have any real effect on your garden, as long as the garden is getting full sun otherwise. And even if it were strong enough to have an effect, light that’s in the red wavelength promotes blooming and fruiting in plants, which is a good thing for crops.
I think I messed up
OK I bought corn kernels to plant and just did it today but I must have misread the label and planted my corn at 6 inches will it survive and germinate on time, die, or survive but not germinate on time. Not just this but the label on the bag says sell by December 2017 and now its April 23 2018 will it be ok and does the label even matter to me or just the seller.
Corn Planting Depth
Six inches is too deep for corn—2 inches is generally the best depth to plant the kernels at. Since you only planted them yesterday, there’s still time to dig them up and replant them a little shallower. They shouldn’t have any trouble germinating after being replanted.
As for the Sell By date, don’t worry about that! Corn kernels can remain viable for years if stored properly (in a freezer), so a few months past their Sell By date won’t affect them at all.
Eating mature sweet corn that has been "frosted"
I've been told that humans cannot eat corn once the frost has hit in the fall. Is this true and if so, why?
The Effects of Frost on Corn
Hi Janell,
That is not true. If the corn has not matured by the time a late-season frost hits, the plants and cobs can be damaged and result in the death of the plant or poor-tasting corn. You can still eat it, but it may not taste very good.
corn
Hi - this is my 1st time growing corn, and have run into a problem. The leaves look "rusty" and the stalks have some rusty looking spots. What to do, and are the ears, that are almost ripe, be saved? Thanks!
Rust-Infected Corn
Hi Sandy,
It sounds like your corn is infected with rust, a fungus disease that can greatly reduce the yield of your crops. There’s not much you can do at this point in preventing the rust, but the ears of corn can be eaten safely, though they may be poor-tasting depending on if the rust infected the ears specifically.
growing corn
I have shoots coming up on outside of corn stalks. Why and what should I do about it?
Secondary Corn Stalks: "Tillers"
Small shoots that appear alongside the base of a primary corn stalk are known as “tillers.” These secondary stalks are actually a good sign; they mean that your plant is healthy and your soil is well-conditioned. Tillers are not an issue and generally won’t compete significantly with the central stalk, but if you’d like to be sure, you can simply cut them off at their bases.
Pruning Sweet Corn
I am thinking about planting corn and I have done enough research to allow me to speak pidgeon corn.
After much of the research I have done on sweet corn, I have found that a stalk will produce between one and two usable cobs, in the variety I am planting. And may produce other non-usable cobs.
I was wondering, If I trim off all but two baby cobs as the stalk is growing, will the plant put more energy into the two remaining cobs giving me a better chance of producing two good cobs per plant.
Or would it not make a difference and I may actually trim off what would become one of my two good cobs?
Thank You for any help you can offer.
an ear for corn
David, We must be perfectly honest with you: After the research you say you have done, you have much more knowledge about corn than we do! But we will concur with you, based on the (il)logical comparison to peaches, with which we have some knowledge (but, it must to said, not much luck). Peach growers are advised to remove/prune small fruits to allow a smaller but better harvest. We think that the same would apply to corn. And it seems to apply to other plants, such as melons and pumpkin. After all, if the plant puts its energy into the remaining “fruit” (or ears, in this case), wouldn’t it be as good as it can be?! Assuming every other aspect of the growing conditions are favorable, of course. We say, trim the ears off those stalks! And, if you feel it might be of value, leave a few stalks alone; don’t trim them, and see, come fall, which method seems most productive.
And let us know how this goes, would you?
Crows and critters ate the seed Corn
I know it's not Recommended to start Sweet Corn indoors, but in recent years I have seen it in market pack for sale as transplants And questioned why at the time. BUT Last year the crows got most of my seed. Would planting seed in the netted expanding peat disks 2-3 weeks before time to plant outdoors stunt the plants? I have an adequate light setup for tomatoes and peppers, etc. I think it would at least let them germinate, Could I plant them at 4 inches high without problems, or will I fail to get corn if I do?
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