One of the best tools that you have as gardeners to help us determine 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 you can plant marigold by reviewing the USDA zone info.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost.

You can not plant marigold until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant marigold 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 marigold and expect a good harvest is probably September. Any later than that and your marigold may not have a chance to fully mature. You can get started a little bit earlier by starting your marigold indoors.

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.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for San Diego and it will vary from year to year. Half of the time in San Diego it frosts late in the year after January 31 so be sure to be ready to protect your marigold in the event of 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 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.