The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for River Falls should be used to determine when it's a good idea to plant bee balm.

Planting Calendar for Bee Balm

Frost tolerance for bee balm:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since bee balm are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant bee balm in River Falls 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 bee balm and expect a good harvest is probably August. Any later than that and your bee balm may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your bee balm indoors.

Last Frost Date

The average date of last frost is May 15 in River Falls. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for River Falls and it changes from year to year. Half of the time in River Falls it frosts late in the year after May 15 so just be sure to be ready to cover your bee balm if you have a surprise late frost.

USDA Zone Info for River Falls

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 River Falls

You may be interested in your other planting guides for River Falls.