Frost damage on Bouganvilea

Frost damage on Bouganvilea
Originally uploaded by dewelch.

Who says it never gets cold in Southern California? I found these frost damaged Bouganvilea as we walked up to the local coffee shop this afternoon.

I am seeing more and more damage almost everywhere I look now. Sitting out on the back patio I finally noticed that the tops of some of the large ficus trees had a bit of damage, too. It seems that almost every tropical plant suffered some damage. Since we don't usually get temperatures this low, the majority of the tropicals are in the ground, rather than in pots, so there is no easy way to protect them, except by tarping or wrapping them in place. On a previous trip to Phoenix, Arizona I saw a lot of this, especially at the large golf resorts which are heavily planted with tropicals, even though they are in an even less tropical area than we are.

The actual damage from frost comes from ice that forms inside each cell of the plant. As water freezes, it increases in volume, swelling the cell until it bursts. This moisture then evaporates away leaving a limp, dessicated leaf or flower behind. In some cases, frost damage can even resemble rot.

I hope I don't need to worry much about frosts in the future, but now I certainly know I need to pay more attention the next time it arrives.