The USDA Zone info is a great tool for gardeners to help us figure out 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 estimating when it's the best time to plant yarrow is to refer to the USDA zone info for Zone 6a.

Planting Calendar for Yarrow

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

You can plant yarrow much earlier in the year because they do well in cold.

The earliest that you can plant yarrow in Zone 6a 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. If you wait any later than that and your yarrow may not have a chance to really do well. 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 Zone 6a. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Zone 6a is just an average the actual date of last frost changes from year to year. Since half of the time in Zone 6a it frosts late in the year after April 15 be ready to cover your yarrow in the event of a surprise late frost.

USDA Zone Info for Zone 6a

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 Zone 6a

You may be interested in your other planting guides for Zone 6a.