One of the first steps you take when you are getting a good idea 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.

A common way of getting a good idea when it's the best time to plant watermelon is to check out the USDA zone info for San Marcos.

Planting Calendar for Watermelon

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

You should not plant watermelon until after all chance of frost has passed because they do not do well in cold weather.

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

The last month that you can plant watermelon and expect a good harvest is probably August. Any later than that and your watermelon may not have a chance to fully mature. You can get started a few weeks earlier by starting your watermelon indoors.

Last Frost Date

The average date of last frost is March 15 in San Marcos. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for San Marcos is not always accurate the actual date of last frost is different every year. Since half of the time in San Marcos last frost occurs after March 15 be ready to cover your watermelon in the event of a surprise 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.