Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant cardinal flower in Washington should be estimated by using the USDA zone info.

Planting Calendar for Cardinal Flower

Frost tolerance for cardinal flower:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since cardinal flower do not do well in cold weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant cardinal flower in Washington is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant cardinal flower and expect a good harvest is probably August. If you wait any later than that and your cardinal flower may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your cardinal flower indoors.

Last Frost Date

The average date of last frost is April 15 in Washington. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Washington is just an average the actual date of last frost is different every year. Half of the time in Washington you get a frost after April 15 so make sure that you are prepared to cover your cardinal flower in the event of one of those late frosts.

USDA Zone Info for Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Washington

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