Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 watermelon in San Bernardino can be figured out by looking at the USDA zone info.

Planting Calendar for Watermelon

Frost tolerance for watermelon:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Watermelon are not cold tolerant which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

The average date of last frost is February 15 in San Bernardino. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that USDA zone info for San Bernardino is just an average and the actual date of last frost is different every year. Half of the time in San Bernardino it frosts late in the year after February 15 so always be ready to protect your watermelon if you have one of those late frosts.

USDA Zone Info for San Bernardino

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 Bernardino

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