Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant lobelia in San Diego can be determined by referring to the USDA zone info.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Lobelia are one of those plants that can tolerate quite a bit of cold weather which means that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant lobelia in San Diego 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 lobelia and expect a good harvest is probably October. You probably don't want to wait any later than that or else your lobelia may not have a chance to really do well. Starting your lobelia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In San Diego the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for San Diego may not be accurate from year to year the actual date of last frost is different every year. Half of the time in San Diego last frost occurs after February 15 so be sure to be ready to protect your lobelia if you have one of those late frosts.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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