The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant calliopsis in Houston should be estimated by looking at the USDA zone info.

Planting Calendar for Calliopsis

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

Since calliopsis do not do well in cold weather you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant calliopsis 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 calliopsis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your calliopsis may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your calliopsis indoors.

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Houston and it will vary from year to year. Half of the time in Houston there is a last frost after February 15 so make sure that you are prepared to protect your calliopsis in the event of a surprise late frost.

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.