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.

The USDA zone info for River Falls can be reviewed to figure out when it's the best time to plant angel's trumpets.

Planting Calendar for Angel's Trumpets

Frost tolerance for angel's trumpets:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since angel's trumpets are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

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

The last month that you can plant angel's trumpets and expect a good harvest is probably August. If you wait any later than that and your angel's trumpets may not have a chance to fully mature. Starting your angel's trumpets indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in River Falls. You can expect an average low temperature of -25°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for River Falls and it is different every year. Half of the time in River Falls it frosts late in the year after May 15 so just be sure to be ready to protect your angel's trumpets 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.