Tropicals & Tender Perennials: «:::H:::» «:::E:::» «:::A:::» «:::T:::», 1 by Clare_CA

Clare_CA wrote:
SB, I don't think that anyone has determined those figures yet. Here in Southern California, many growers keep their plumerias outside all year long, and we had record cold temps this past winter. Many had several sustained hours of 27F and reported tip damage and even death of large trees. I had several nights of 32F and a two-hour period of 28F but sustained no damage except for two tips. I did throw a tarp over most of my plumerias during that night of 28F.

Normally, the nighttime winter temps don't go much below 40F here. It might dip down to the mid- to high-30's for a few hours in the early morning before the sun comes up. With these sort of mild temps, most of my plumerias don't go dormant, keep their leaves, and need water. With the cold temps that we had this winter, 95% of my plumerias lost their leaves. However, I continue to water when the soil looks dry, which is about every other day. That said, I have things in my yard which create warm microclimates, I'm sure. Such as three-quarter rock instead of grass, aluminum side paneling on the house, and a six-foot surrounding concrete retaining wall. I'm also up against a major four-lane street with street lights and more concrete.

I haven't found an optimum temp for plumerias, but it seems that the more heat they get, the better that they do provided that they have plenty of water. They thrive in places like Australia, Thailand, Hawaii, Mexico, India, Indonesia, and Panama; however, they need good drainage and will not do well in those places where there is too much rain. Growers grow them successfully in places like Arizona, Nevada, and Texas, where there is a great amount of heat. It seems that, as long as water and/or humidity is present, maximum heat is preferable. HTH

Edited to fix spacing.

This message was edited Mar 30, 2007 11:23 AM