Before planting it is a good idea to find your USDA Zone info to estimate 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.

In New Haven you can estimate when it's a good idea to plant yarrow by reviewing the USDA zone info.

Planting Calendar for Yarrow

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

Yarrow are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them much earlier than other frost tender plants.

The earliest that you can plant yarrow in New Haven 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 grow to maturity. Starting your yarrow indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in New Haven. In the coldest months of winter you should expect an average low temperature of -10°F.

Remember that USDA zone info for New Haven is just an average and the actual date of last frost changes from year to year. Half of the time in New Haven you get surprised by a frost after April 15 so make sure that you are ready to cover your yarrow if you have a surprise late frost.

USDA Zone Info for New Haven

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 New Haven

You may be interested in your other planting guides for New Haven.