Before planting it is a good idea to find your USDA Zone info to determine 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.

In Riverside you can determine when to plant trailing portulaca by checking out the USDA zone info.

Planting Calendar for Trailing Portulaca

Frost tolerance for trailing portulaca:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant trailing portulaca until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant trailing portulaca in Riverside 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. You probably don't want to wait any later than that or else your trailing portulaca may not have a chance to grow to maturity. You can get started a little bit earlier by starting your trailing portulaca indoors.

Last Frost Date

In Riverside the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Riverside and it is different every year. Half of the time in Riverside you get a frost after February 15 so always be ready to cover your trailing portulaca in the event of one of those late frosts.

USDA Zone Info for Riverside

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 Riverside

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