One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when you can plant polygonums by looking at the USDA zone info for Bothell.

Planting Calendar for Polygonums

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

You can not plant polygonums until after all chance of frost has passed because they require warm weather.

The earliest that you can plant polygonums in Bothell 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 polygonums and expect a good harvest is probably August. You probably don't want to wait any later than that or else your polygonums may not have a chance to really do well. You can get started a couple of weeks earlier by starting your polygonums indoors.

Last Frost Date

In Bothell the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

It's important to remember 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 Bothell and it can change quite a bit from year to year. Half of the time in Bothell you get surprised by a frost after March 15 so always be ready to protect your polygonums if you have a late frost.

USDA Zone Info for Bothell

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 Bothell

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