One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when you can plant tall phlox is to refer to the USDA zone info for Fairfax.

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 Fairfax 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 grow to maturity. Starting your tall phlox indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Fairfax. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Fairfax is an average and the actual date of last frost is different every year. Since half of the time in Fairfax last frost occurs after February 15 be ready to protect your tall phlox if you have one of those late frosts.

USDA Zone Info for Fairfax

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Fairfax

You may be interested in your other planting guides for Fairfax.