Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant tall phlox in Houston can be figured out by using the USDA zone info.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant tall phlox just a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant tall phlox in Houston is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably October. Any later than that and your tall phlox may not have a chance to really do well. You can get started a few weeks earlier by starting your tall phlox indoors.

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.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Houston and it is different every year. Since half of the time in Houston you get surprised by a frost after February 15 be ready to cover your tall phlox 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.