The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when to plant yarrow is to examine the USDA zone info for Cambridge.

Planting Calendar for Yarrow

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

Yarrow tend to make it in quite a bit of cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Cambridge 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 yarrow and expect a good harvest is probably September. You probably don't want to wait any later than that or else your yarrow may not have a chance to fully mature. If you are starting your yarrow indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Cambridge the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that USDA zone info for Cambridge may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Cambridge there is a last frost after April 15 so just be sure to be ready to cover your yarrow if you have a surprise late frost.

USDA Zone Info for Cambridge

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 Cambridge

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