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

In Marlborough you can estimate when to plant achillea by looking at 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.

Achillea do well in a bit of cold which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Marlborough 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. 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

On average the last frost when the weather gets warmer is on April 15 in Marlborough. In the coldest months of winter you should expect an average low temperature of -10°F.

Remember that USDA zone info for Marlborough is just an average and the actual date of last frost changes from year to year. Half of the time in Marlborough last frost occurs after April 15 so always be ready to protect your achillea in the event of a surprise late frost.

USDA Zone Info for Marlborough

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Marlborough

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