One of the first steps you take when you are estimating your gardening schedule is find your 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.

One way of determining when it's possible to plant polygonums is to examine the USDA zone info for Seward.

Planting Calendar for Polygonums

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

It's probably a bad idea to plant polygonums until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant polygonums in Seward 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 fully mature. If you are starting your polygonums 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 Seward. It might get as low as -15°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Seward and it will vary from year to year. Half of the time in Seward last frost occurs after April 15 so always be ready to cover your polygonums in the event of one of those late frosts.

USDA Zone Info for Seward

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 Seward

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