The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 Houston should be read to estimate when it's a good idea to plant torenia.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Torenia are not cold tolerant which tells us that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant torenia in Houston 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 torenia and expect a good harvest is probably September. Any later than that and your torenia may not have a chance to grow to maturity. If you are starting your torenia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Houston. You should expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Houston is not always accurate the actual date of last frost changes from year to year. Half of the time in Houston you get surprised by a frost after February 15 so make sure that you are ready to cover your torenia 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.