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.

The best time to plant columbine in Zone 6b can 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 do well in moderate cold 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 columbine in Zone 6b 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. Starting your columbine indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Zone 6b. In the coldest months of winter you should expect an average low temperature of -5°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Zone 6b and it can change quite a bit from year to year. Half of the time in Zone 6b it frosts late in the year after April 15 so make sure that you are prepared to cover your columbine in the event of a late frost.

USDA Zone Info for Zone 6b

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 Zone 6b

You may be interested in your other planting guides for Zone 6b.