One of the first steps you take when you are estimating 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.

One way of making a decision about when it's possible to plant polygonums is to refer to the USDA zone info for Bellevue.

Planting Calendar for Polygonums

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

Polygonums require warm weather which tells us that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant polygonums in Bellevue 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. Any later than that and your polygonums may not have a chance to grow to maturity. If you are starting your polygonums indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Bellevue. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Bellevue is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Bellevue it frosts late in the year after March 15 be ready to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Bellevue

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 Bellevue

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