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

In Napa you can figure out when it's possible to plant tall phlox by using the USDA zone info.

Planting Calendar for Tall Phlox

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

Tall Phlox are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Napa 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. If you wait any later than that and your tall phlox may not have a chance to really do well. Starting your tall 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 Napa. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Napa is just an average and the actual date of last frost is different every year. Since half of the time in Napa you get a frost after February 15 be ready to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for Napa

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 Napa

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