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.

One way of determining when to plant tomatos is to look at the USDA zone info for San Juan.

Planting Calendar for Tomatos

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

Tomatos are not cold tolerant which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant tomatos in San Juan 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. You probably don't want to wait any later than that or else your tomatos may not have a chance to fully mature. 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

On average the last frost has passed is on February 15 in San Juan. It might get as low as 25°F during the coldest months of winter.

Always keep in mind 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 Juan and it is different every year. Since half of the time in San Juan last frost occurs after February 15 be ready to protect your tomatos if you have a surprise late frost.

USDA Zone Info for San Juan

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in San Juan

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