One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when it's possible to plant angel's trumpets by using the USDA zone info for Owatonna.

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.

You can plant angel's trumpets slightly earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant angel's trumpets in Owatonna 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. Any later than that and your angel's trumpets may not have a chance to really do well. If you are starting your angel's trumpets indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Owatonna the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Owatonna is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Owatonna there is a last frost after May 15 be ready to cover your angel's trumpets in the event of one of those late frosts.

USDA Zone Info for Owatonna

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 Owatonna

You may be interested in your other planting guides for Owatonna.