Before planting it is a good idea to find your USDA Zone info to figure out 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 string beans in Portland should be estimated by using the USDA zone info.

Planting Calendar for String beans

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

Since string beans do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant string beans in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant string beans and expect a good harvest is probably September. You probably don't want to wait any later than that or else your string beans may not have a chance to really do well. If you are starting your string beans indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Portland the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Remember that USDA zone info for Portland is just an average and the actual date of last frost is different every year. Half of the time in Portland you get surprised by a frost after February 15 so make sure that you are ready to protect your string beans if you have a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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