ARS Master Rosarian
By Frank Brines, ARS Master Rosarian
In southern California winter is usually short and sometimes confusing. Winter for some plant life is a time of withdrawal that precedes renewal. For roses it is necessary to help them in that process. Now is the time to perform a few procedures to help reset the hormonal clock and get them ready for a great year of rose blooms. That’s the main purpose for pruning.
According to experienced rosarians, the proper time for the major annual pruning is “late winter.” This has many meanings in an area like So Cal which has numerous weather zones. Bottom line: Prune late enough to avoid risking frost damage to the tender growth that will emerge as a result of pruning. After this pruning, you can usually expect a flush of blooms 8 to 12 weeks later, depending on the temperatures during that period—the warmer it is, the shorter the time to blooms. But all things being equal, if you prune in the latter half of February you will likely have blooms in mid- to late-April. If you want blooms for a specific date, count backwards approximately 10 weeks from that date. Pruning should be complete on this date.
In most of our region the last average frost date is mid March, so that means you’re probably safe pruning in mid- to late-February. It is always a gamble and the best advice is to watch the weather. If there is winter rain during January/February, pruning can be held off awhile since these rains are cold making the ground colder and wetter than usual.
If you haven’t began or finished pruning by now, don’t fear: There is still plenty of time to have blooms for rose shows or special spring events!