Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Sullivan you can estimate when it's possible to plant achillea by reviewing 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.

You can plant achillea a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant achillea in Sullivan 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. If you are starting your achillea indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Sullivan 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.

It's important to remember that USDA zone info for Sullivan is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Sullivan it frosts late in the year after April 15 so just be sure to be ready to protect your achillea in the event of a late frost.

USDA Zone Info for Sullivan

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 Sullivan

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