One of the best tools that you have as gardeners to help us estimate 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.

You will be able to estimate when it's possible to plant polygonums by referring to the USDA zone info for Hartland.

Planting Calendar for Polygonums

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

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

The earliest that you can plant polygonums in Hartland 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. Starting your polygonums indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Hartland the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Just be sure 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 Hartland and it will vary from year to year. Half of the time in Hartland 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 Hartland

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 Hartland

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