One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

By reviewing the USDA zone info for Harrisburg you should be able to estimate when you can plant achillea.

Planting Calendar for Achillea

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

You can plant achillea earlier in the year because they do well in cold.

The earliest that you can plant achillea in Harrisburg 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 achillea and expect a good harvest is probably September. You probably don't want to wait any later than that or else your achillea may not have a chance to fully mature. If you are starting your achillea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Harrisburg the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Remember that USDA zone info for Harrisburg may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Harrisburg you get surprised by a frost after April 15 so make sure that you are ready to cover your achillea if you have a late frost.

USDA Zone Info for Harrisburg

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 Harrisburg

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