One of the first steps you take when you are getting a good idea 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.

The earliest that you can plant campanula in Washington can be estimated by referring to the USDA zone info.

Planting Calendar for Campanula

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

You can plant campanula 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 campanula 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 campanula and expect a good harvest is probably September. Any later than that and your campanula may not have a chance to grow to maturity. Starting your campanula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Washington. It might get as low as 10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Washington and it changes from year to year. Since half of the time in Washington last frost occurs after March 15 be ready to cover your campanula if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Washington

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