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.

In San Diego you can figure out when it's the best time to plant regal geranium by using the USDA zone info.

Planting Calendar for Regal Geranium

Frost tolerance for regal geranium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant regal geranium slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant regal geranium in San Diego is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant regal geranium and expect a good harvest is probably September. If you wait any later than that and your regal geranium may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your regal geranium indoors.

Last Frost Date

In San Diego the average date of last frost happens on January 31. You can expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for San Diego is not always accurate the actual date of last frost is different every year. Half of the time in San Diego you get surprised by a frost after January 31 so just be sure to be ready to protect your regal geranium if you have a surprise late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Diego

You may be interested in your other planting guides for San Diego.