One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when you can plant columbine is to use the USDA zone info for Stillwater.

Planting Calendar for Columbine

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

Columbine do well in moderate cold which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant columbine in Stillwater 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. If you wait any later than that and your columbine may not have a chance to really do well. You can get started a couple of weeks earlier by starting your columbine indoors.

Last Frost Date

The average date of last frost is May 15 in Stillwater. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Stillwater and it will vary from year to year. Half of the time in Stillwater you get surprised by a frost after May 15 so just be sure to be ready to protect your columbine if you have one of those late frosts.

USDA Zone Info for Stillwater

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Stillwater

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