The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Dover should be looked at to estimate when it's the best time to plant astilbe.

Planting Calendar for Astilbe

Frost tolerance for astilbe:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Astilbe do well in a tiny bit of cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant astilbe in Dover is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant astilbe and expect a good harvest is probably August. You probably don't want to wait any later than that or else your astilbe may not have a chance to really do well. Starting your astilbe indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Dover the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Dover and it can change quite a bit from year to year. Half of the time in Dover you get a frost after April 15 so always be ready to cover your astilbe 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.