One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By looking at the USDA zone info for La Crosse you should be able to determine when it's the best time to plant polygonums.

Planting Calendar for Polygonums

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

Since polygonums are not cold tolerant it is important to wait until after the last frost before you can plant them.

The earliest that you can plant polygonums in La Crosse 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. Any later than that and your polygonums may not have a chance to grow to maturity. Starting your polygonums indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in La Crosse. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for La Crosse and it can change quite a bit from year to year. Half of the time in La Crosse it frosts late in the year after May 15 so be sure to be ready to protect your polygonums in the event of a late frost.

USDA Zone Info for La Crosse

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 La Crosse

You may be interested in your other planting guides for La Crosse.