When to Plant Lobelia in San Diego, CA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 estimated by looking at 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.

You can plant lobelia a lot earlier in the year because they are very cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant lobelia
Possibly ok, but a risky time to plant lobelia
Probably not a good time to plant lobelia

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. If you wait any later than that and 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

On average the last frost has passed is on January 31 in San Diego. It might get as low as 35°F during the coldest months of winter.

Just be sure to remember that USDA zone info for San Diego is an average and the actual date of last frost will vary from year to year. Since half of the time in San Diego last frost occurs after January 31 be ready to cover your lobelia if you have a 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 Low35°F
Highest Expected Low40°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.