One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's the best time to plant tall phlox by referring to the USDA zone info for Pomona.

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 moderately cold tolerant which tells us that you can plant them earlier than plants that are more sensitive to the cold.

The earliest that you can plant tall phlox in Pomona 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. 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 little bit earlier.

Last Frost Date

In Pomona the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Pomona is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Pomona you get surprised by a frost after January 31 be ready to cover your tall phlox in the event of a late frost.

USDA Zone Info for Pomona

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 Pomona

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