The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant corn in Washington can be figured out by checking out the USDA zone info.

Planting Calendar for Corn

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

It's probably not a good idea to plant corn until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant corn in Washington 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 fully mature. If you are starting your corn indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Washington is an average and the actual date of last frost will vary from year to year. Since half of the time in Washington last frost occurs after April 15 be ready to cover your corn if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Washington

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