One of the first steps you take when you are determining 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 Marcos should be reviewed to estimate when to plant lobelia.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Lobelia can survive in quite a bit of cold which tells us that you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant lobelia 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 lobelia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your lobelia may not have a chance to grow to maturity. Starting your lobelia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In San Marcos the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for San Marcos is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in San Marcos it frosts late in the year after March 15 so be sure to be ready to protect your lobelia if you have one of those late frosts.

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.