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.

By using the USDA zone info for San Marcos it's a good idea to determine when it's possible to plant iceberg lettuce.

Planting Calendar for Iceberg lettuce

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

Iceberg lettuce are barely cold tolerant which tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost has passed is on March 15 in San Marcos. You can expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that USDA zone info for San Marcos is not always accurate and the actual date of last frost will vary from year to year. Half of the time in San Marcos last frost occurs after March 15 so make sure that you are prepared to cover your iceberg lettuce in the event of a late frost.

USDA Zone Info for San Marcos

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in San Marcos

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