Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when to plant achillea is to look at the USDA zone info for Muskego.

Planting Calendar for Achillea

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

Since achillea are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Muskego is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant achillea and expect a good harvest is probably September. Any later than that and your achillea may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your achillea indoors.

Last Frost Date

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

Since the USDA zone info for Muskego may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Muskego last frost occurs after April 15 be ready to cover your achillea if you have one of those late frosts.

USDA Zone Info for Muskego

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Muskego

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