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 estimate when it's possible to plant scarlet runner beans in Lake Oswego by reviewing the USDA zone info.

Planting Calendar for Scarlet Runner Beans

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

Since scarlet runner beans are not cold tolerant you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant scarlet runner beans in Lake Oswego 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 scarlet runner beans and expect a good harvest is probably August. Any later than that and your scarlet runner beans may not have a chance to fully mature. If you are starting your scarlet runner beans indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Lake Oswego. In the coldest months of winter you should expect an average low temperature of 15°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Lake Oswego and it can change quite a bit from year to year. Since half of the time in Lake Oswego you get a frost after March 15 be ready to cover your scarlet runner beans if you have a surprise late frost.

USDA Zone Info for Lake Oswego

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Lake Oswego

You may be interested in your other planting guides for Lake Oswego.