Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Three Rivers it's possible to figure out when to plant yarrow.

Planting Calendar for Yarrow

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

Since yarrow are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Three Rivers 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. Any later than that and your yarrow may not have a chance to grow to maturity. If you are starting your yarrow indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Three Rivers the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Three Rivers and it is different every year. Half of the time in Three Rivers last frost occurs after April 15 so make sure that you are prepared to protect your yarrow in the event of a surprise late frost.

USDA Zone Info for Three Rivers

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Three Rivers

You may be interested in your other planting guides for Three Rivers.