Posted January 28, 2007, 10:41 AM.

The frost threat can continue for most of the winter, so in most Western Riverside County locations, the conservative answer is late March.

For places like Fallbrook and De Luz, late February or early March might work, although it may already be safe in some of the warmer parts of those areas.

In colder locations such as Sun City, you may want to wait until April. However, if you live in a colder location, you may want to think about planting frost or freeze sensitive plants at all, because it freezes there so often in an average winter.

In recent years in Temecula, where WeatherCurrents has the most data, the estimated last frost occurred on March 19th. Thus, if you were a Temecula resident and you planted after that date this decade, your plants were safe, at least until the next winter.