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

You should be able to figure out when it's possible to plant yarrow by referring to the USDA zone info for Mount Horeb.

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 get them planted much earlier than more sensitive plants.

The earliest that you can plant yarrow in Mount Horeb 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Mount Horeb. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Mount Horeb is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Mount Horeb you get a frost after April 15 be ready to cover your yarrow in the event of a late frost.

USDA Zone Info for Mount Horeb

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Mount Horeb

You may be interested in your other planting guides for Mount Horeb.