The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant columbine in River Forest should be estimated by reviewing the USDA zone info.

Planting Calendar for Columbine

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

Since columbine are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant columbine in River Forest 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. Any later than that and your columbine may not have a chance to really do well. If you are starting your columbine indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in River Forest. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for River Forest is an average and the actual date of last frost is different every year. Half of the time in River Forest it frosts late in the year after April 15 so make sure that you are prepared to protect your columbine if you have a late frost.

USDA Zone Info for River Forest

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 River Forest

You may be interested in your other planting guides for River Forest.