Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant achillea in Bozeman should be estimated by referring to the USDA zone info.

Planting Calendar for Achillea

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

You can plant achillea earlier in the year because they do well in cold.

The earliest that you can plant achillea 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 achillea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your achillea may not have a chance to fully mature. Starting your achillea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Bozeman is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Bozeman there is a last frost after May 15 so make sure that you are ready to cover your achillea 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.