One of the best tools that you have as gardeners to help us estimate 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 figure out when it's possible to plant cardinal flower by looking at the USDA zone info for Sulphur.

Planting Calendar for Cardinal Flower

Frost tolerance for cardinal flower:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant cardinal flower until after the last frost has passed because they require warm weather.

The earliest that you can plant cardinal flower in Sulphur is March. However, you really should wait until April 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 grow to maturity. You can get started a little bit earlier by starting your cardinal flower indoors.

Last Frost Date

The average date of last frost is February 15 in Sulphur. In the coldest months of winter you can expect an average low temperature of 20°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Sulphur and it changes from year to year. Half of the time in Sulphur you get surprised by a frost after February 15 so make sure that you are prepared to protect your cardinal flower in the event of one of those late frosts.

USDA Zone Info for Sulphur

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sulphur

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