The USDA Zone info is a great tool for gardeners to help us figure out 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.

You will be able to determine when it's a good idea to plant tall phlox by reviewing the USDA zone info for South Houston.

Planting Calendar for Tall Phlox

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

Tall Phlox do ok in moderate cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in South 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. You probably don't want to wait any later than that or else your tall phlox may not have a chance to fully mature. You can get started a little bit earlier by starting your tall phlox indoors.

Last Frost Date

In South Houston the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for South Houston and it will vary from year to year. Half of the time in South Houston there is a last frost after February 15 so just be sure to be ready to protect your tall phlox in the event of a surprise late frost.

USDA Zone Info for South 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 South Houston

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