One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 USDA zone info for River Falls can be used to estimate when it's the best time to plant sweet woodruff.

Planting Calendar for Sweet Woodruff

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

Sweet Woodruff do well in moderate cold which tells us that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant sweet woodruff 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 sweet woodruff and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet woodruff may not have a chance to really do well. If you are starting your sweet woodruff indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in River Falls. In the coldest months of winter you should 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. Half of the time in River Falls you get surprised by a frost after May 15 so be sure to be ready to cover your sweet woodruff in the event of 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.