Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when it's the best time to plant yarrow by referring to the USDA zone info for Commerce.

Planting Calendar for Yarrow

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

Yarrow are very cold tolerant which means that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant yarrow in Commerce 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 really do well. You can get started a few weeks earlier by starting your yarrow indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Commerce. In the coldest months of winter you should expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Commerce and it is different every year. Half of the time in Commerce it frosts late in the year after March 15 so always be ready to protect your yarrow if you have one of those late frosts.

USDA Zone Info for Commerce

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Commerce

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