Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant hardy asters in Mattoon can be figured out by reviewing 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.

Hardy Asters are barely cold tolerant which tells us that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant hardy asters in Mattoon 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 grow to maturity. Starting your hardy asters indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Mattoon. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mattoon and it will vary from year to year. Half of the time in Mattoon last frost occurs after April 15 so make sure that you are prepared to cover your hardy asters if you have a surprise late frost.

USDA Zone Info for Mattoon

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Mattoon

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