Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's a good idea to plant phlox is to refer to the USDA zone info for South Pasadena.

Planting Calendar for Phlox

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

Phlox tend to make it in moderate cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant phlox in South Pasadena 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 phlox and expect a good harvest is probably October. Any later than that and your phlox may not have a chance to fully mature. If you are starting your phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in South Pasadena. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for South Pasadena may not be accurate from year to year the actual date of last frost is different every year. Half of the time in South Pasadena it frosts late in the year after January 31 so make sure that you are ready to cover your phlox in the event of a surprise late frost.

USDA Zone Info for South Pasadena

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in South Pasadena

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