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

A common way of determining when to plant achillea is to look at the USDA zone info for Gardiner.

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 a bit of cold which tells us that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Gardiner 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. If you wait any later than that and your achillea may not have a chance to fully mature. You can get started a few weeks earlier by starting your achillea indoors.

Last Frost Date

In Gardiner the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Gardiner may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Gardiner you get a frost after April 15 be ready to protect your achillea in the event of a late frost.

USDA Zone Info for Gardiner

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Gardiner

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