One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant squash in Washington can be estimated by referring to the USDA zone info.

Planting Calendar for Squash

Frost tolerance for squash:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since squash require warm weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant squash 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 squash and expect a good harvest is probably August. If you wait any later than that and your squash may not have a chance to fully mature. If you are starting your squash indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Washington. It might get as low as -15°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Washington and it can change quite a bit from year to year. Half of the time in Washington you get surprised by a frost after April 15 so always be ready to protect your squash in the event of a 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.