The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant phlox is to refer to the USDA zone info for Corona.

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 Corona 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 really do well. Starting your phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on February 15 in Corona. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Corona is an average the actual date of last frost changes from year to year. Half of the time in Corona last frost occurs after February 15 so always be ready to protect your phlox in the event of a late frost.

USDA Zone Info for Corona

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 Corona

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