Before planting it is a good idea to find your USDA Zone info to estimate 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 USDA zone info for Southlake should be reviewed to estimate when it's the best time 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.

Cardinal Flower are not cold tolerant which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant cardinal flower in Southlake 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 fully mature. If you are starting your cardinal flower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Southlake the average date of last frost happens on March 15. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Southlake is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Southlake it frosts late in the year after March 15 so just be sure to be ready to protect your cardinal flower in the event of one of those late frosts.

USDA Zone Info for Southlake

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Southlake

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