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

By checking out the USDA zone info for Sunnyvale it's possible to determine when it's a good idea to 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 do well in moderate cold which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant phlox in Sunnyvale 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 grow to maturity. Starting your phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Sunnyvale. 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 Sunnyvale is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Sunnyvale you get a frost after February 15 be ready to cover your phlox in the event of a late frost.

USDA Zone Info for Sunnyvale

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 Sunnyvale

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