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

The first opportunity to plant cardinal flower in Oakland should be figured out by reviewing 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 has passed.

You should not plant cardinal flower until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant cardinal flower in Oakland 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. 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

On average the last frost is on April 15 in Oakland. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Oakland is not always accurate the actual date of last frost is different every year. Half of the time in Oakland you get surprised by a frost after April 15 so be sure to be ready to cover your cardinal flower in the event of one of those late frosts.

USDA Zone Info for Oakland

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 Oakland

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