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

The first chance to plant polygonums in Griffith can be determined by reviewing the USDA zone info.

Planting Calendar for Polygonums

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

You really shouldn't plant polygonums until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant polygonums in Griffith 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 fully mature. Starting your polygonums indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Griffith is just an average and the actual date of last frost will vary from year to year. Half of the time in Griffith you get surprised by a frost after April 15 so make sure that you are ready to protect your polygonums if you have one of those late frosts.

USDA Zone Info for Griffith

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 Griffith

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