The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Bozeman should be looked at 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 are very cold tolerant which means that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant anchusa in Bozeman 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 fully mature. 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

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

It's important to remember that USDA zone info for Bozeman is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Bozeman you get surprised by a frost after May 15 be ready to cover your anchusa if you have one of those late frosts.

USDA Zone Info for Bozeman

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 Bozeman

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