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

You can estimate when you can plant asters in Oak Brook by referring to the USDA zone info.

Planting Calendar for Asters

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

You can plant asters a little earlier in the year because they do well in moderate cold.

The earliest that you can plant asters in Oak Brook 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. You probably don't want to wait any later than that or else your asters may not have a chance to fully mature. You can get started a little bit earlier by starting your asters indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Oak Brook. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Oak Brook is just an average the actual date of last frost is different every year. Half of the time in Oak Brook it frosts late in the year after April 15 so make sure that you are prepared to protect your asters in the event of a late frost.

USDA Zone Info for Oak Brook

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 Oak Brook

You may be interested in your other planting guides for Oak Brook.