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

One way of figuring out when it's a good idea to plant yarrow is to examine the USDA zone info for Williamsport.

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 tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

In Williamsport the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Williamsport is an average the actual date of last frost will vary from year to year. Half of the time in Williamsport you get a frost after April 15 so just be sure to be ready to protect your yarrow in the event of a late frost.

USDA Zone Info for Williamsport

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Williamsport

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