The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant trifolium in San Diego can be estimated by looking at the USDA zone info.

Planting Calendar for Trifolium

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

Since trifolium are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant trifolium 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 trifolium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your trifolium may not have a chance to really do well. If you are starting your trifolium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in San Diego. You should expect an average low temperature of 20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for San Diego may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in San Diego last frost occurs after February 15 so be sure to be ready to protect your trifolium 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.