When to Plant Sweet corn in Zone 1a

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Zone 1a can be read to estimate when it's the best time to plant sweet corn.


Planting Calendar for Sweet corn

Frost tolerance for sweet corn: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since sweet corn are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sweet corn
Possibly ok, but a risky time to plant sweet corn
Probably not a good time to plant sweet corn

The earliest that you can plant sweet corn in Zone 1a is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant sweet corn and expect a good harvest is probably July. You probably don't want to wait any later than that or else your sweet corn may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your sweet corn indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on June 15 in Zone 1a. You can expect an average low temperature of -60°F in the coldest months of winter.

Keep in mind that USDA zone info for Zone 1a is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 1a last frost occurs after June 15 be ready to cover your sweet corn if you have one of those late frosts.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-60°F
Highest Expected Low-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.