One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. 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 determine when it's the best time to plant astilbe by referring to the USDA zone info for Franklin.

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 are barely cold tolerant which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant astilbe in Franklin 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. Any later than that and your astilbe may not have a chance to grow to maturity. Starting your astilbe indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Franklin. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Franklin may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Franklin last frost occurs after April 15 so be sure to be ready to protect your astilbe in the event of a surprise late frost.

USDA Zone Info for Franklin

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 Franklin

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