When to Plant Corn in Hermiston, OR

One of the first steps you take when you are estimating your gardening schedule is find your 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 earliest that you can plant corn in Hermiston should be estimated by referring to the USDA zone info.


Planting Calendar for Corn

Frost tolerance for corn: Not tolerant of frost.
When to plant: After the last frost has passed.

Corn are not cold tolerant which means that it's important to wait until it warms up after the last frost before you can plant them.

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

The earliest that you can plant corn in Hermiston is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant corn and expect a good harvest is probably August. Any later than that and your corn may not have a chance to grow to maturity. Starting your corn indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Hermiston. You should expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Hermiston is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Hermiston you get surprised by a frost after April 15 so make sure that you are ready to protect your corn if you have a surprise late frost.

USDA Zone Info for Hermiston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Hermiston

You may be interested in your other planting guides for Hermiston.