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

A way of making a decision about when it's possible to plant columbine is to check out the USDA zone info for Zone 3a.

Planting Calendar for Columbine

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

Columbine can survive in some cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant columbine in Zone 3a is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant columbine and expect a good harvest is probably August. Any later than that and your columbine may not have a chance to fully mature. 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

In Zone 3a the average date of last frost happens on May 15. It might get as low as -40°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 3a and it will vary from year to year. Half of the time in Zone 3a you get a frost after May 15 so always be ready to cover your columbine if you have a surprise late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-40°F
Highest Expected Low	-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.