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

By reviewing the USDA zone info for River Falls it's possible to determine when it's the best time to plant asters.

Planting Calendar for Asters

Frost tolerance for asters:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Asters are moderately cold tolerant which tells us that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant asters 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 asters and expect a good harvest is probably August. You probably don't want to wait any later than that or else your asters may not have a chance to really do well. Starting your asters indoors is a great way to get them started a little bit earlier.

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 USDA zone info for River Falls is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in River Falls there is a last frost after May 15 so be sure to be ready to protect your asters 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.