One of the first steps you take when you are figuring out your gardening schedule is find your 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.

You can estimate when it's possible to plant achillea in Worland by reviewing 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.

Since achillea are very cold tolerant you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant achillea in Worland 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. You can get started a few weeks earlier by starting your achillea indoors.

Last Frost Date

In Worland the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Worland is not always accurate and the actual date of last frost is different every year. Since half of the time in Worland you get surprised by a frost after May 15 be ready to cover your achillea in the event of a late frost.

USDA Zone Info for Worland

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 Worland

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