One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to determine when it's the best time to plant columbine by checking out the USDA zone info for Naperville.

Planting Calendar for Columbine

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

You can plant columbine a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant columbine in Naperville 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 columbine and expect a good harvest is probably September. If you wait any later than that and your columbine may not have a chance to fully mature. You can get started a little bit earlier by starting your columbine indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Naperville is an average and the actual date of last frost is different every year. Half of the time in Naperville you get surprised by a frost after April 15 so just be sure to be ready to cover your columbine if you have a surprise late frost.

USDA Zone Info for Naperville

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 Naperville

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