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.

In Irvine you can determine when it's a good idea to plant tall phlox by referring to 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 do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant tall phlox in Irvine 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 fully mature. Starting your tall phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Irvine. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Irvine may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Irvine you get surprised by a frost after January 31 so just be sure to be ready to cover your tall phlox if you have a surprise late frost.

USDA Zone Info for Irvine

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 Irvine

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