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

A common way of making a decision about when you can plant astilbe is to check out the USDA zone info for Deerfield.

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.

Since astilbe do ok in moderate cold you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

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

Since the USDA zone info for Deerfield is just an average the actual date of last frost changes from year to year. Half of the time in Deerfield last frost occurs after April 15 so always be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Deerfield

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Deerfield

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