Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 estimating when you can plant achillea is to look at the USDA zone info for Mendham.

Planting Calendar for Achillea

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

Achillea do ok in pretty solid cold which means that you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant achillea in Mendham 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. You probably don't want to wait any later than that or else your achillea may not have a chance to grow to maturity. Starting your achillea indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Mendham. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Mendham is just an average the actual date of last frost changes from year to year. Since half of the time in Mendham it frosts late in the year after April 15 be ready to cover your achillea in the event of one of those late frosts.

USDA Zone Info for Mendham

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 Mendham

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