Plumeria during the winter

Leaf drop:

We receive calls during the winter saying "My tree dropped all or most of its leaves, what should I do".  Well first of all, this perfectly normal for plumeria.  Winter days are shorter, providing less light to the trees, therefore not enough energy to produce leaves and or flowers and consequently leaves drop from the tree.

Cold damage:

Fighting mother nature the last three years has taught us a lot about cold weather and plumeria.  Here in west south central Florida historically, we could expect 2 to 3 nights a year for temps to drop around or slightly below freezing. The past two winters we have been down to 25 and even 20 degrees two winters ago for multiple nights.  This year so far we have had 2 close calls when it got as low as 30 degrees two nights. Other than those two night we just about have not had any winter.  It has been great.  I have only warn a coat three days all winter. 

I realize this only applies in locales where winter is not too harsh.  Watching winter closely for the past 24 years I have come to the following conclusion.Plumeria are pretty cold hardy right around 32 degrees plus or minus a degree or two.  Humidity plays a very important part in how plants are affected, the higher the humidity the more possible damage due to teh presence of frost and or ice.  We have intentionally left plumerias out of greenhouses  on freezing nights to see how they would handle the cold.  Much to our surprise plants sitting under the canopy of an oak tree received no damage with temperature at 30 degree for many hours.  The canopy of the oak tree helped to hold down heat that escapes from the ground on cold nights, much as a greenhouse does.  I feel quite confident this would not be the case when the temperatures got to the low 20's.