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

By checking out the USDA zone info for San Mateo it's a good idea to determine when to plant cardinal flower.

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 are not cold tolerant you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant cardinal flower in San Mateo 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 cardinal flower and expect a good harvest is probably September. You probably don't want to wait any later than that or else your cardinal flower may not have a chance to fully mature. 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 January 31 in San Mateo. In the coldest months of winter you should expect an average low temperature of 30°F.

Remember that USDA zone info for San Mateo is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in San Mateo there is a last frost after January 31 be ready to protect your cardinal flower if you have one of those late frosts.

USDA Zone Info for San Mateo

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Mateo

You may be interested in your other planting guides for San Mateo.