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

A way of determining when to plant columbine is to consult the USDA zone info for Radcliff.

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 moderately cold tolerant you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant columbine in Radcliff 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 grow to maturity. You can get started a little bit earlier by starting your columbine indoors.

Last Frost Date

On average the last frost is on April 15 in Radcliff. It might get as low as -5°F during the coldest months of winter.

Keep in mind that USDA zone info for Radcliff is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Radcliff last frost occurs after April 15 so just be sure to be ready to cover your columbine in the event of a surprise late frost.

USDA Zone Info for Radcliff

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Radcliff

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