The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Milliken can be read to estimate when to plant columbine.

Planting Calendar for Columbine

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

Columbine tend to make it in moderate cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant columbine in Milliken 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. You probably don't want to wait any later than that or else your columbine may not have a chance to really do well. 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

On average all chance of frost has passed is on April 15 in Milliken. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Milliken and it changes from year to year. Half of the time in Milliken you get surprised by a frost after April 15 so be sure to be ready to protect your columbine in the event of a surprise late frost.

USDA Zone Info for Milliken

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Milliken

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