Before planting it is a good idea to find your USDA Zone info to determine your garden 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 can be used to determine when you can plant bidens.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since bidens require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant bidens in River Falls is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant bidens and expect a good harvest is probably August. If you wait any later than that and your bidens may not have a chance to really do well. Starting your bidens indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In River Falls the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that the actual date of last frost is not always accurate 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 you get surprised by a frost after May 15 so always be ready to cover your bidens if you have a 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.