One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's possible to plant hardy hibiscus in River Falls by reviewing the USDA zone info.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus do well in pretty solid cold which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant hardy hibiscus in River Falls is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably August. If you wait any later than that and your hardy hibiscus may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

On average the last frost has passed is on May 15 in River Falls. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for River Falls may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in River Falls there is a last frost after May 15 be ready to cover your hardy hibiscus if you have one of those late frosts.

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.