Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant columbine in Douglas 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.

You can plant columbine just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant columbine in Douglas 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. You probably don't want to wait any later than that or else 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 couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Douglas. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Douglas and it changes from year to year. Since half of the time in Douglas you get a frost after May 15 be ready to protect your columbine if you have one of those late frosts.

USDA Zone Info for Douglas

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 Douglas

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