It’s difficult to think of any crop that is more important the world over than corn. Corn is used in so many foods, either directly or through its many derivatives like corn syrup, that there are a whole lot of things that would simply disappear if there was no more corn.
Corn is cheap and plentiful because of the gargantuan scale that it is grown at agriculturally, but it’s possible to grow your own corn at home with a little preparation. On that note, just how much sun does corn need every day?
All modern corn varieties need at least 10 hours of sunlight every single day. More is generally better, but there are some varieties that will still produce with slightly less sunlight.
In general, corn needs three things in order to thrive: lots of space, protection from pests, and lots and lots of sunlight.
If you can provide those, your corn will probably do well. If you can’t, you’re probably going to have a bad time. I’ll tell you more in the rest of this article…
Is Full Sun Best for Corn?
Absolutely! All corn, at least all modern varieties of corn, are going to need full sun, all the time, every single day.
How Many Hours of Sun a Day is Best for Corn?
Generally, corn should be getting no less than 10 hours of direct, full sunlight daily. Plenty of sun will ensure adequate photosynthesis, high yield and high-quality kernels that are sweet and crisp.
If you want a good haul of corn, just make sure it gets plenty of sun!
Now, your corn isn’t going to perish if it gets a little less than 10 hours a day, but less sun means lower yield most of the time.
It will also significantly slow down the growth of the corn, meaning that enough cloudy days or too much shading might put your harvest behind.
That being said, things always happen, so do your best and as long as your corn is getting 10 hours a day of sunlight more often than not it should do well.
Will Too Much Sun Hurt Corn?
Only rarely. Like I said above more sun is almost always better for corn, but there are occasions when temperatures are really soar that too much prolonged sun might be harmful.
When this happens, the corn will lose its sweetness, and the kernels will begin to toughen. When the plant is really struggling to deal with these extreme temperatures, you’ll notice the leaves yellowing, wilting, or even showing sunscald spots.
Most of the time, the only time you will need to worry about your corn getting too much sun is in the middle of a genuine heat wave.
In such times, if you’re able to shade your corn from the worst of the afternoon sun, then you should, at least for a couple of hours.
Does Corn Do Well in Indirect Sun?
No. Corn will only tolerate indirect sun for a very small percentage of the time, and even then only if most of the day is in full, direct sun.
It might theoretically be possible to grow corn in predominantly indirect sunlight, but I can guarantee you that it will not produce a yield anywhere near what it would in direct sun.
This naturally can cause problems for people who have a property that is constantly shaded by tall trees, or for folks who want to try to grow corn indoors.
Will Corn Thrive in Shade?
No way. Corn just needs way too much full, direct sun in order to prosper.
What Happens to Corn That Doesn’t Get Enough Sun?
When corn is suffering from a lack of sunlight, you’ll know. Generally, they quickly start to slow down and then die off with leaves yellowing, and stalks thinning out.
This stress might prompt the plants to produce a few stunted ears of corn, but by then it is too late typically.
Even if you try to rally it with proper care, or if conditions improve, it might go on to produce more ears, but you should manage your expectations in this case: its ears are likely to be small and taste bland.
Corn needs lots of sunlight for photosynthesis that will enable the production of sugar that makes the kernels taste so good. No light means no sugar, and that means bland corn!
Sun Requirements for Different Corn Varieties
There are tons of corn varieties on the market today, some of that are a little bit closer to heritage strains than others.
This selection is further complicated by the subtypes: there’s a field corn and sweet corn, and each of those has various colors, from the traditional yellow to white, blue, and even multicolored.
Each and every one of them has its own specific requirements, but cutting to the chase there’s no variety of corn today that needs any less than 8 hours of sunlight each and every day, and most need closer to the prescribed 10 hours of sun that I’ve mentioned several times already.
But, if you want a variety of corn that requires the least possible amount of sun, look for a blue variety of field corn since they tend to need significantly less than other kinds.
Tips for Bringing Indoor Corn Outside
If you’re trying to grow corn indoors, you are either half crazy or truly desperate.
It’s not that corn simply cannot be grown indoors, only that it is extremely difficult – owing to its intense sunlight requirements, and also the fact that it usually transplants very, very poorly.
But if you think you’re up to the task and are getting ready to move your corn outdoors after successfully starting it inside, you must take the time to do it right and harden it off.
Hardening off refers to a process of placing the corn outside in a shady spot for a couple of hours each day before bringing it back inside.
With every day that passes, leave it outside for just a little while longer and then repeat this process for a couple of weeks.
This must be done after the last risk of frost: corn, including sweet corn, will not tolerate frost, even a light one. Heck, most corn varieties don’t tolerate a chill!
Generally, the temperature must not drop below 50°F or your corn will be in trouble.
By following this tedious but necessary process, you will acclimatize the corn to the outside environment and reduce shock that will occur if you just take it outside straight away and transplant it.
Your corn already has the deck stacked against it with you just trying to transplant it, so you should do everything you can to improve your chances of success if you are serious.
Tom has lived and worked on farms and homesteads from the Carolinas to Kentucky and beyond. He is passionate about helping people prepare for tough times by embracing lifestyles of self-sufficiency.