One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 Washington should be reffered to in order to determine when you can plant calendula.

Planting Calendar for Calendula

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

Calendula can survive in some cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant calendula 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 calendula and expect a good harvest is probably September. If you wait any later than that and your calendula may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your calendula indoors.

Last Frost Date

The average date of last frost is April 15 in Washington. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Washington is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Washington it frosts late in the year after April 15 be ready to cover your calendula in the event of a late frost.

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.