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.

You should be able to estimate when it's the best time to plant cardinal flower by using the USDA zone info for Oakland.

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.

It's not a good idea to plant cardinal flower until after the last frost 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. If you wait any later than that and your cardinal flower may not have a chance to fully mature. If you are starting your cardinal flower indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Oakland the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 5°F.

Keep in mind that USDA zone info for Oakland may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Oakland last frost occurs after April 15 be ready to cover your cardinal flower in the event of a late frost.

USDA Zone Info for Oakland

Here is the info for USDA Zone 7b.

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

Plants to Grow in Oakland

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