One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

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

Planting Calendar for Achillea

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

Achillea can survive in cold weather which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Somerville 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. 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

In Somerville the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for Somerville is not always accurate and the actual date of last frost is different every year. Half of the time in Somerville you get surprised by a frost after April 15 so make sure that you are ready to cover your achillea in the event of a surprise late frost.

USDA Zone Info for Somerville

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 Somerville

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