The USDA Zone info is a great tool for gardeners to help us determine 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 earliest that you can plant astilbe in Pontiac should be determined by looking at 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 are barely cold tolerant which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant astilbe in Pontiac 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 couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Pontiac is just an average the actual date of last frost is different every year. Since half of the time in Pontiac you get surprised by a frost after April 15 be ready to protect your astilbe if you have one of those late frosts.

USDA Zone Info for Pontiac

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 Pontiac

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