One of the first steps you take when you are figuring out your gardening schedule is find your 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.

In South Holland you can estimate when to plant achillea by checking out the USDA zone info.

Planting Calendar for Achillea

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

Since achillea are one of those plants that can tolerate quite a bit of cold weather 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 achillea in South Holland 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. Any later than that and 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 South Holland the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for South Holland is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in South Holland it frosts late in the year after April 15 be ready to protect your achillea in the event of a late frost.

USDA Zone Info for South Holland

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in South Holland

You may be interested in your other planting guides for South Holland.