Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant squash in Washington should be determined by referring to the USDA zone info.

Planting Calendar for Squash

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

Since squash are not cold tolerant it's necessary 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. You probably don't want to wait any later than that or else your squash may not have a chance to really do well. You can get started a little bit earlier by starting your squash indoors.

Last Frost Date

On average the last frost is on March 15 in Washington. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Washington may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Washington there is a last frost after March 15 be ready to protect your squash if you have one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

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

Plants to Grow in Washington

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