One of the first steps you take when you are estimating 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.

The USDA zone info for Duluth can be looked at to figure out when you can plant achillea.

Planting Calendar for Achillea

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

Achillea do ok in cold weather which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Duluth 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. Any later than that and your achillea may not have a chance to grow to maturity. If you are starting your achillea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Duluth the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Remember that USDA zone info for Duluth is an average and the actual date of last frost is different every year. Half of the time in Duluth you get surprised by a frost after May 15 so always be ready to cover your achillea in the event of a surprise late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Duluth

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