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

It's possible to figure out when you can plant campanula by using the USDA zone info for Oak Brook.

Planting Calendar for Campanula

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

Campanula can survive in moderate cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant campanula 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 campanula and expect a good harvest is probably September. If you wait any later than that and your campanula may not have a chance to fully mature. If you are starting your campanula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Oak Brook is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Oak Brook there is a last frost after April 15 so make sure that you are prepared to protect your campanula 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.