When to Plant Polygonums in Madison, WI

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

The first chance to plant polygonums in Madison can be estimated 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.

Since polygonums are not cold tolerant you really should wait until after the last frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant polygonums
Possibly ok, but a risky time to plant polygonums
Probably not a good time to plant polygonums

The earliest that you can plant polygonums in Madison 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. 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

In Madison the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

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 Madison and it will vary from year to year. Since half of the time in Madison it frosts late in the year after April 15 be ready to protect your polygonums in the event of one of those late frosts.

USDA Zone Info for Madison

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Madison

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