The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when it's the best time to plant yarrow is to examine the USDA zone info for Mechanicsburg.

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 very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Mechanicsburg 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. You probably don't want to wait any later than that or else your yarrow may not have a chance to grow to maturity. Starting your yarrow indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Mechanicsburg. In the coldest months of winter you can expect an average low temperature of 0°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Mechanicsburg and it changes from year to year. Half of the time in Mechanicsburg there is a last frost after April 15 so be sure to be ready to protect your yarrow if you have one of those late frosts.

USDA Zone Info for Mechanicsburg

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Mechanicsburg

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