One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant trailing portulaca in Houston should be estimated by reviewing the USDA zone info.

Planting Calendar for Trailing Portulaca

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

You can not plant trailing portulaca until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant trailing portulaca 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 trailing portulaca and expect a good harvest is probably September. If you wait any later than that and your trailing portulaca may not have a chance to really do well. If you are starting your trailing portulaca indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is 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 may not be accurate from year to year 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 trailing portulaca if you have 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.