One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

In River Falls you can estimate when to plant violas by looking at the USDA zone info.

Planting Calendar for Violas

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

Violas tend to make it in pretty solid cold which tells us that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant violas 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 violas and expect a good harvest is probably August. If you wait any later than that and your violas may not have a chance to grow to maturity. Starting your violas indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for River Falls and it will vary from year to year. Half of the time in River Falls last frost occurs after May 15 so make sure that you are ready to cover your violas 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.