One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Sun Prairie you can estimate when it's possible 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 start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant yarrow in Sun Prairie 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 grow to maturity. Starting your yarrow indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Sun Prairie. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Sun Prairie may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Sun Prairie it frosts late in the year 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 Sun Prairie

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 Sun Prairie

You may be interested in your other planting guides for Sun Prairie.