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.

The USDA zone info for Houston should be reviewed to estimate when it's possible to plant calibrachoa.

Planting Calendar for Calibrachoa

Frost tolerance for calibrachoa:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Calibrachoa do ok in some cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant calibrachoa in Houston 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 calibrachoa and expect a good harvest is probably September. You probably don't want to wait any later than that or else your calibrachoa may not have a chance to really do well. Starting your calibrachoa indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Houston. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Houston is an average and the actual date of last frost changes from year to year. Since half of the time in Houston there is a last frost after February 15 be ready to cover your calibrachoa in the event of one of those late frosts.

USDA Zone Info for Houston

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 Houston

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