The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant achillea by using the USDA zone info for Hummelstown.

Planting Calendar for Achillea

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

Achillea are very cold tolerant which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant achillea in Hummelstown 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. You can get started a few weeks earlier by starting your achillea indoors.

Last Frost Date

In Hummelstown the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Hummelstown and it changes from year to year. Since half of the time in Hummelstown it frosts late in the year after April 15 be ready to protect your achillea if you have a surprise late frost.

USDA Zone Info for Hummelstown

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 Hummelstown

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