The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Clarendon Hills you can determine when it's the best time to plant hardy asters by looking at the USDA zone info.

Planting Calendar for Hardy Asters

Frost tolerance for hardy asters:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since hardy asters are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hardy asters in Clarendon Hills 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 hardy asters and expect a good harvest is probably August. Any later than that and your hardy asters may not have a chance to fully mature. Starting your hardy asters 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 Clarendon Hills. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Clarendon Hills is an average the actual date of last frost is different every year. Since half of the time in Clarendon Hills there is a last frost after April 15 be ready to protect your hardy asters if you have a surprise late frost.

USDA Zone Info for Clarendon Hills

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 Clarendon Hills

You may be interested in your other planting guides for Clarendon Hills.