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.

You can determine when you can plant squash in Portland 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 has passed.

Squash require warm weather which means that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Portland. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Portland may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Portland it frosts late in the year after April 15 so be sure to be ready to protect your squash in the event of one of those late frosts.

USDA Zone Info for Portland

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 Portland

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