One of the best tools that you have as gardeners to help us determine 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 Owatonna should be reviewed to figure out when to plant anchusa.

Planting Calendar for Anchusa

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

Since anchusa do well in cold you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant anchusa in Owatonna 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 anchusa and expect a good harvest is probably August. Any later than that and your anchusa may not have a chance to really do well. If you are starting your anchusa indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Owatonna. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Owatonna is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Owatonna you get a frost after May 15 so be sure to be ready to protect your anchusa in the event of a late frost.

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.