One of the first steps you take when you are figuring out 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.

In Dekalb you can determine when it's the best time to plant astilbe by referring to the USDA zone info.

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 start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Dekalb 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. If you wait any later than that and your astilbe may not have a chance to fully mature. Starting your astilbe indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Dekalb is not always accurate the actual date of last frost is different every year. Since half of the time in Dekalb it frosts late in the year after April 15 be ready to cover your astilbe in the event of one of those late frosts.

USDA Zone Info for Dekalb

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 Dekalb

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