The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In San Luis Obispo you can figure out when it's possible to plant watermelon by referring to the USDA zone info.

Planting Calendar for Watermelon

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

Watermelon do not do well in cold weather which tells us that it's necessary to 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 Luis Obispo 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 grow to maturity. If you are starting your watermelon indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Luis Obispo and it changes from year to year. Since half of the time in San Luis Obispo you get surprised by a frost after February 15 be ready to protect your watermelon in the event of a late frost.

USDA Zone Info for San Luis Obispo

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 Luis Obispo

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