One of the first steps you take when you are making a decision about 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 first chance to plant petunias in San Marcos should be estimated by using the USDA zone info.

Planting Calendar for Petunias

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

You can plant petunias a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant petunias in San Marcos 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 petunias and expect a good harvest is probably September. If you wait any later than that and your petunias may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your petunias indoors.

Last Frost Date

On average the last frost has passed is on January 31 in San Marcos. You can expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Marcos may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in San Marcos you get surprised by a frost after January 31 be ready to cover your petunias in the event of a surprise late frost.

USDA Zone Info for San Marcos

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Marcos

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