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.

In Winona you can figure out when it's possible to plant polygonums by referring to the USDA zone info.

Planting Calendar for Polygonums

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

You really shouldn't plant polygonums until after the last frost because they require warm weather.

The earliest that you can plant polygonums in Winona is May. However, you really should wait until June 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. If you wait any later than that and your polygonums may not have a chance to really do well. If you are starting your polygonums indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Winona the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Winona and it can change quite a bit from year to year. Since half of the time in Winona last frost occurs after May 15 be ready to protect your polygonums in the event of a surprise late frost.

USDA Zone Info for Winona

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Winona

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