One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's a good idea to plant columbine is to check out the USDA zone info for Washington.

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 a little earlier in the year because they do well in moderate cold.

The earliest that you can plant columbine in Washington 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. Any later than that and your columbine may not have a chance to really do well. Starting your columbine indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Washington. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Washington may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Washington you get a frost after April 15 be ready to cover your columbine in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Washington

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