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.

A way of determining when it's the best time to plant lupine is to consult the USDA zone info for River Falls.

Planting Calendar for Lupine

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

Lupine do well in moderate cold which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant lupine 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 lupine and expect a good harvest is probably August. You probably don't want to wait any later than that or else your lupine may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your lupine indoors.

Last Frost Date

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

Since the USDA zone info for River Falls is just an average the actual date of last frost is different every year. Half of the time in River Falls last frost occurs after May 15 so make sure that you are prepared to protect your lupine 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.