Out of all the things that you might grow in your garden, corn is undeniably the most important from an economic and industrial perspective.
Used as a food on its own, an ingredient in all kinds of other foods, and with derivatives used in all sorts of industrial processes and fuel, corn is definitely an economic powerhouse.
But that is a conversation for another day. We are just trying to grow corn for ourselves. So how much sun does corn need?
Corn always needs abundant, full sun, preferably 10 hours a day. Corn can still grow well, if a little bit slower, with around eight hours of sun a day. Any less than that will spell trouble for your corn.
Corn isn’t particularly difficult to grow so long as you have plenty of light and plenty of space. Most of its other requirements can be met easily enough.
Keep reading to learn everything you need to know about the light requirements of corn.
Do Corn Need Full Sun?
Yes, always. Corn needs tons of sunshine day in and day out if it is going to thrive. This is not a plant that does well in partial sun or shade. It needs full, direct sunlight for the majority of the day.
How Many Hours of Sun Does Corn Need?
Ideally, your corn plants should be getting 10 hours of direct sunlight each and every day. This is the amount of light that they need in order to grow optimally.
So long as your corn gets this much light, they will grow quickly and produce plenty of ears for you to enjoy.
That being said, corn plants can still do reasonably well even if they only get 8 hours of sunlight each day. They will just grow a bit more slowly and might not produce as many ears.
So, if you only have 8 hours of sunlight available for your corn plants each day, don’t despair: They just might take them a little longer to reach maturity and you might not get as high of a yield.
Can Corn Grow in Shade?
Not at all. Corn plants need full, direct and copious sunlight in order to grow properly. They cannot tolerate shade for any significant portion of the day.
If your corn plants are not getting enough sunlight, they will quickly start to suffer.
Can Corn Get Too Much Sun?
Not really. This is one crop that is pretty difficult to overload with sunlight. They really do need as much direct sunlight as you can give them.
That being said, too much intense sun in conjunction with high temperatures can harm corn over time.
While it’s true that corn needs tons of sun to thrive, too much sun and heat can cause the corn kernels to toughen and become less sweet. In extreme cases, the leaves of the plant may scorch or turn yellow.
So while a little bit of extra sunshine is often good for your corn crop, don’t let them get too much sun during a heatwave or you might end up with a disappointing harvest.
Do Different Varieties of Corn Need More or Less Sun?
With so many different types of corn on the market, it can be hard to know which one to plant in your garden.
Do you want sweet corn or field corn? White, yellow, or blue? And how much sun does each type need? It turns out that the answer to this last question is not always straightforward.
While most varieties of corn need at least eight hours of sunlight per day to produce, there are some cultivars that can thrive on that amount.
In general, sweet corn needs more sun than field corn, and white and yellow varieties need more sun than blue.
However, there are always exceptions to the “rules” of color, so it is always best to check the specifics before planting.
By doing a little research ahead of time, you can be sure to choose the right type of corn for your garden setup.
What Happens if Corn Doesn’t Get Enough Sun?
Corn needs a lot of sun to live, much less thrive. This is because corn is what is known as a “long-day” plant.
This means that it needs more than 8 hours of sunlight each day in order to flower and produce ears of corn.
If your corn plants are not getting enough sun, they will quickly start to suffer. The leaves will turn yellow and the stalks will become thin and spindly.
The plant might produce a few small ears of corn, but the yield will be significantly lower than it would be if the plant was getting enough sunlight.
Without enough sun, the corn plant will not be able to photosynthesize properly, and the resulting lack of sugar will stunt its growth. In some cases, the plant may even die.
However, if the corn plant does manage to survive, it will still likely produce fewer and smaller ears of corn.
In short, if you want your corn plants to reach their full potential, make sure they are getting at least 10 hours of direct sunlight each day.
Can Corn Grow in Indirect Sun?
No, at least not if it is getting indirect sun for the majority of the time. While corn plants do need full, direct sunlight to grow properly, they can tolerate some indirect sunlight for a small part of the day as long as the rest of the day is sun soaked.
However, if your corn plants are getting mostly indirect light, they will not perform as well as they would in full sun. It is difficult, but possible, to sprout and even start corn plants indoors with enough work.
However, once the corn plants have reached a certain size, they will need to be moved outdoors so that they can get the sunlight they need to grow properly.
If you have a window sunroom that gets a lot of natural light, that could be a good place to put your corn plants for a little while, but chances are they will still need plenty of time under a grow light for maximum benefit.
Transitioning Corn from Indoors to Sunlight
The true trick with starting corn indoors does not come from sprouting it, but rather when the time comes to transplant it.
Corn does not transplant well, at all, and you’ll need to take some extra care when moving your corn plants outdoors.
First, set yourself up for success by planting your “indoor” corn in a large container. A large bucket or tub works well.
This will make it easier to move the corn plant, roots and all, when the time comes. When your corn plants are about a foot tall and have several leaves, they are ready to be moved outdoors.
Second, you’ll need to “harden off” your corn plants. This is the process of slowly acclimating them to the outdoors so that they do not experience too much shock when transplanting.
Start by putting them outside in a shady spot for a few hours each day. Gradually increase the amount of time they spend outdoors and in direct sunlight each day until they are able to stay outside all day without issue. This process will take at least a week, more likely two.
Once your corn plants are hardened off, it is time to transplant them into your garden. Choose a spot that gets full sun for at least 10 hours each day.
Carefully remove the corn plant from its container, taking care not to damage the roots, the place and tamp.
Tom has built and remodeled homes, generated his own electricity, grown his own food and more, all in quest of remaining as independent of society as possible. Now he shares his experiences and hard-earned lessons with readers around the country.
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