One of the first steps you take when you are determining 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.

It's possible to estimate when it's possible to plant achillea by referring to the USDA zone info for Zone 6b.

Planting Calendar for Achillea

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

Achillea are one of those plants that can tolerate quite a bit of cold weather which tells us that you can start planting them much earlier than more sensitive plants.

The earliest that you can plant achillea in Zone 6b 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 really do well. If you are starting your achillea indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Zone 6b the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Keep in mind that USDA zone info for Zone 6b is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 6b there is a last frost after April 15 be ready to protect your achillea in the event of a late frost.

USDA Zone Info for Zone 6b

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 Zone 6b

You may be interested in your other planting guides for Zone 6b.