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.

A common way of estimating when it's the best time to plant snap beans is to look at the USDA zone info for Portland.

Planting Calendar for Snap beans

Frost tolerance for snap beans:	Not tolerant of frost.
When to plant:	After the last frost.

Since snap beans are not cold tolerant you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant snap beans 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 snap beans and expect a good harvest is probably August. You probably don't want to wait any later than that or else your snap beans may not have a chance to grow to maturity. If you are starting your snap beans indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Portland and it will vary from year to year. Half of the time in Portland you get a frost after April 15 so make sure that you are ready to protect your snap beans 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.