One of the first steps you take when you are figuring out 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 tall phlox in San Antonio should be estimated 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.

Tall Phlox do well in a little bit of cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tall phlox in San Antonio is February. However, you really should wait until March 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 September. If you wait any later than that and your tall phlox may not have a chance to grow to maturity. Starting your tall phlox indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on March 15 in San Antonio. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for San Antonio is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in San Antonio you get a frost after March 15 be ready to protect your tall phlox in the event of a surprise late frost.

USDA Zone Info for San Antonio

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in San Antonio

You may be interested in your other planting guides for San Antonio.