One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's possible to plant yarrow is to refer to the USDA zone info for Mankato.

Planting Calendar for Yarrow

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

Yarrow tend to make it in cold weather which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Mankato is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant yarrow and expect a good harvest is probably August. You probably don't want to wait any later than that or else your yarrow may not have a chance to fully mature. Starting your yarrow indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Mankato the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mankato and it can change quite a bit from year to year. Since half of the time in Mankato there is a last frost after May 15 be ready to protect your yarrow if you have one of those late frosts.

USDA Zone Info for Mankato

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Mankato

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