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.

By reviewing the USDA zone info for Decorah you will be able to estimate when it's a good idea 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.

Anchusa do well in cold weather which means that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant anchusa in Decorah 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. You probably don't want to wait any later than that or else your anchusa may not have a chance to fully mature. Starting your anchusa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Decorah 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 Decorah may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Decorah last frost occurs after May 15 so just be sure to be ready to protect your anchusa if you have a surprise late frost.

USDA Zone Info for Decorah

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 Decorah

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