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.

You can determine when it's the best time to plant columbine in Stewartville by looking at 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.

You can plant columbine just a bit earlier in the year because they do well in moderate cold.

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

Last Frost Date

On average the last frost has passed is on May 15 in Stewartville. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Stewartville is an average the actual date of last frost changes from year to year. Since half of the time in Stewartville you get surprised by a frost after May 15 be ready to protect your columbine if you have a surprise late frost.

USDA Zone Info for Stewartville

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 Stewartville

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