One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant achillea in Dover should be determined by using 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.

Achillea can survive in a bit of cold which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Dover 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

On average the last frost is on April 15 in Dover. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that USDA zone info for Dover is just an average and the actual date of last frost is different every year. Since half of the time in Dover there is a last frost after April 15 be ready to cover your achillea if you have one of those late frosts.

USDA Zone Info for Dover

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 Dover

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