One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Lisle you will be able to figure out when it's the best time to plant asters.

Planting Calendar for Asters

Frost tolerance for asters:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since asters do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant asters in Lisle is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant asters and expect a good harvest is probably September. If you wait any later than that and your asters may not have a chance to fully mature. You can get started a few weeks earlier by starting your asters indoors.

Last Frost Date

The average date of last frost is April 15 in Lisle. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Lisle is not always accurate and the actual date of last frost changes from year to year. Half of the time in Lisle you get surprised by a frost after April 15 so make sure that you are ready to cover your asters in the event of one of those late frosts.

USDA Zone Info for Lisle

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 Lisle

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