One of the first steps you take when you are figuring out your gardening schedule is find your 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.

The USDA zone info for San Diego should be used to determine when you can plant tomatos.

Planting Calendar for Tomatos

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

Since tomatos do not do well in cold weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

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

The last month that you can plant tomatos and expect a good harvest is probably September. If you wait any later than that and your tomatos may not have a chance to grow to maturity. If you are starting your tomatos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In San Diego the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for San Diego and it can change quite a bit from year to year. Since half of the time in San Diego you get surprised by a frost after February 15 be ready to protect your tomatos in the event of a surprise late frost.

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.