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.

In Rialto you can determine when it's a good idea to plant tall phlox by reviewing 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 tend to make it in moderate cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Rialto 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. You probably don't want to wait any later than that or else your tall phlox may not have a chance to grow to maturity. If you are starting your tall phlox indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Rialto is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Rialto there is a last frost after January 31 so make sure that you are ready to protect your tall phlox in the event of a late frost.

USDA Zone Info for Rialto

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 Rialto

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