One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Humble you can determine when it's the best time to plant cardinal flower by looking at the USDA zone info.

Planting Calendar for Cardinal Flower

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

Since cardinal flower do not do well in cold weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant cardinal flower in Humble 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 really do well. Starting your cardinal flower indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Humble. It might get as low as 20°F during the coldest months of winter.

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 Humble and it will vary from year to year. Since half of the time in Humble there is a last frost after February 15 be ready to protect your cardinal flower if you have one of those late frosts.

USDA Zone Info for Humble

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 Humble

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