One of the first steps you take when you are estimating 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.

A way of making a decision about when you can plant astilbe is to examine the USDA zone info for Harrisonburg.

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 ok in moderate cold which means that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Harrisonburg 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

In Harrisonburg the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Harrisonburg and it can change quite a bit from year to year. Since half of the time in Harrisonburg you get surprised by a frost after April 15 be ready to protect your astilbe in the event of a surprise late frost.

USDA Zone Info for Harrisonburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Harrisonburg

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