The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant yarrow in Spearfish can be determined 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 do ok in quite a bit of cold which tells us that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant yarrow in Spearfish 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. You can get started a little bit earlier by starting your yarrow indoors.

Last Frost Date

The average date of last frost is April 15 in Spearfish. It might get as low as -20°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Spearfish and it will vary from year to year. Since half of the time in Spearfish last frost occurs after April 15 be ready to protect your yarrow if you have one of those late frosts.

USDA Zone Info for Spearfish

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 Spearfish

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