One of the first steps you take when you are making a decision about 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.

You should be able to estimate when it's the best time to plant achillea by looking at the USDA zone info for Mount Washington.

Planting Calendar for Achillea

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

You can plant achillea much earlier in the year because they are very cold tolerant.

The earliest that you can plant achillea in Mount Washington 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. Starting your achillea indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Mount Washington. It might get as low as -5°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Mount Washington and it will vary from year to year. Since half of the time in Mount Washington last frost occurs after April 15 be ready to cover your achillea if you have a surprise late frost.

USDA Zone Info for Mount Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Mount Washington

You may be interested in your other planting guides for Mount Washington.