One of the best tools that you have as gardeners to help us determine 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.

One way of determining when to plant squash is to examine the USDA zone info for Washington.

Planting Calendar for Squash

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

You should not plant squash until after the last frost because they require warm weather.

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. Any later than that and your squash may not have a chance to grow to maturity. If you are starting your squash indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Washington. It might get as low as -5°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average 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 it frosts late in the year after April 15 so make sure that you are ready to protect your squash in the event of a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

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

Plants to Grow in Washington

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