One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of making a decision about when to plant achillea is to examine the USDA zone info for Winona.

Planting Calendar for Achillea

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

Achillea do well in cold which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant achillea in Winona 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. You can get started a little bit earlier by starting your achillea indoors.

Last Frost Date

In Winona 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.

Since the USDA zone info for Winona is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Winona you get a frost after May 15 so always be ready to cover your achillea if you have a surprise late frost.

USDA Zone Info for Winona

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 Winona

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