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

By referring to the USDA zone info for Costa Mesa you should be able to estimate when you can plant phlox.

Planting Calendar for Phlox

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

Phlox can survive in a little bit of cold which means 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 phlox in Costa Mesa 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. If you wait 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 couple of weeks earlier.

Last Frost Date

In Costa Mesa the average date of last frost happens on January 31. You can expect an average low temperature of 35°F in the coldest months of winter.

Remember that USDA zone info for Costa Mesa may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Costa Mesa last frost occurs after January 31 so make sure that you are prepared to protect your phlox if you have one of those late frosts.

USDA Zone Info for Costa Mesa

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Costa Mesa

You may be interested in your other planting guides for Costa Mesa.