One of the best tools that you have as gardeners to help us determine 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.

One way of making a decision about when to plant columbine is to refer to the USDA zone info for Oak Ridge.

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 little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant columbine in Oak Ridge 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 fully mature. Starting your columbine indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Oak Ridge the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 5°F.

It's important to remember that USDA zone info for Oak Ridge may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Oak Ridge you get surprised by a frost after April 15 so always be ready to protect your columbine in the event of one of those late frosts.

USDA Zone Info for Oak Ridge

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Oak Ridge

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