Sweet corn is popular in home gardens because it is delicious and easy to grow. But you might be wondering if you can grow sweet corn in cold weather.
Corn grows best in weather between 75 and 86 degrees Fahrenheit (24 and 30°C). While you can grow corn in slightly cooler or warmer weather, growth will be affected by the wide range of temperatures. Freezing temperatures can damage or kill your corn plants, so you’ll want to make sure to grow your corn after the danger of frost is past.
In this article, we’ll take a look at whether or not you can grow corn in cold weather. We’ll look at how long it takes for corn to grow, how early you can plant your corn, and how to find your frost dates to avoid frost damage to your corn. We’ll also give you some tips to keep your corn safe from cold weather. But first, let’s take a quick look at the ideal temperatures for growing corn.
The Ideal Temperature and Climate for Growing Corn
In order to see what’s too cold for corn and how you can protect it on cooler days, let’s take a look at the ideal conditions and climate first.
The ideal climate for growing corn is warm and sunny weather that stays between 75 and 86 degrees Fahrenheit (24 and 30°C) with some moderate rain. If you don’t receive enough rain, you can water or irrigate your corn to make up for it. But in most cases, you’ll need 130 days or more without frost.
Under ideal conditions, corn should germinate in about 10 to 14 days. Ideal conditions include a soil temperature of 60 degrees or higher, moist loamy soil, and not too much rain. If the soil temperature drops to 55 degrees (12.5 °C), it could take your corn up to 22 days to germinate. And even lower than that, your corn might not germinate at all.
If these conditions are met, your corn will germinate quickly, but it will also grow quickly. It should take your corn 60 to 100 days to reach harvest, depending on the variety and as long as there is enough moisture and the appropriate temperature (in this other article I describe how long it takes for corn to grow, and how different factors affect it, as well as some of the fastest-growing corn varieties). But what happens if it gets colder? Will your corn still grow?
How Early in the Season Can You Grow Corn?
Typically, you’ll want to plant corn about 2 to 3 weeks past the last frost date for your area. Keep in mind that this is an estimate based on years of data, but last frost dates can’t be perfectly predicted. However, if you wait too long to plant your corn, you might run out of frost-free days before your corn is ready to harvest.
How Do I Find My Last Frost Date?
The easiest way to find your last frost date is to use this calculator on the Farmer’s Almanac Website. Input your zip code, and it will tell you the expected last frost date for your area. It will also tell your expected first frost date in the fall and the length of your growing season so you can plan the optimum time to plant your corn.
You can also find a planting calendar here, which will tell you when you can plant corn and other vegetables in your garden. These tools will help you know if you can plant corn where you live and how early you can plant it.
What Happens if You Start Corn too Early?
The cold weather can severely stunt your plant growth if you try to plant your corn too early in the season. The plant’s leaves may be discolored if they get too cold. Then again, if cold water from snow or cold rain reaches the germinating plants, they could be deformed and not grow correctly. If the temperatures are too frigid, your plants might even die.
A light frost before the corn has emerged is not likely to cause any damage, although a heavy freeze could kill the plants as they are germinating.
A light freeze may injure delicate seedlings, but they should bounce back if the temperature remains above 28 degrees Fahrenheit (-2°C). If this happens, you should see new growth on the plant within three to five days. If you see new growth, your corn will most likely be able to recover from the shock.
On the other hand, if the temperatures drop below 28 degrees Fahrenheit for even a few minutes, your plants will likely die. You can wait a few days to see if they will recover, but you may end up having to replant your corn with fresh seed.
What Happens if You Start Corn Too Late?
If you plant corn too late in the year, it might be susceptible to an early fall frost. So you’ll need to calculate how long it takes your particular variety of corn to mature. Then, count back the number of growing days from the first frost date to make sure you have enough time to grow your corn.
If your corn does get damaged by frost, you might not see the signs of damage for a few days. The foliage of the corn will look water-soaked at first and then turn brown and dry.
Frost can affect the ears of corn, as well. You might see smaller ears of corn, misshapen ears, or shriveled kernels. If the corn plant survives, you might get poor-quality corn.
It only takes 5 or 10 minutes of 28-degree temperatures (-2°C) to kill corn plants or temperatures of at least 32 degrees Fahrenheit (0°C) for four hours or more.
Tips To Protect Your Corn In Cool Weather
Even if you follow your first and last frost dates, you might still have some unseasonable weather that could damage your corn crop. However, you can take a few precautions to protect your corn as much as possible.
Plant your corn on a slope towards the Sun
This will angle your garden so that the heat of the sun will warm up your garden more during the day. Warmer soils will retain more warmth through the night. Interestingly, the cold air can actually ‘drain’ away from the plants as it rolls down the slope.
Plant your corn near structures that can act as a heat sink
For example, if you plant near a south-facing wall, it will absorb the Sun’s heat during the day and radiate that heat back at night. This may protect your corn from light frost damage.
Plant near trees, boulders, or fences
These structures can help protect plants from cooling winds and trap heat and moisture in the soil, which will create a protective microclimate for your corn. For example, a garden positioned in front of a rock or brick wall benefits from the warmth absorbed by the wall during the day. Then, at night, it will radiate the heat slowly to protect the plants.
Cover your plants
If you are able, you can cover plants when there is a predicted frost. For example, you could cover them with row covers, light sheets, or plastic to keep the heat in and the cold out.