Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant trailing portulaca is to look at the USDA zone info for Petaluma.

Planting Calendar for Trailing Portulaca

Frost tolerance for trailing portulaca:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since trailing portulaca require warm weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant trailing portulaca in Petaluma 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 trailing portulaca and expect a good harvest is probably September. Any later than that and your trailing portulaca may not have a chance to grow to maturity. Starting your trailing portulaca indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Petaluma the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Petaluma is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Petaluma you get a frost after February 15 be ready to protect your trailing portulaca if you have a surprise late frost.

USDA Zone Info for Petaluma

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 Petaluma

You may be interested in your other planting guides for Petaluma.