We decided this winter we would put our house on the market. The goal was to sell and move in the early summer. I was afraid of uprooting many of my tropical plants that normally are out in the yard and established by then, so I decided to keep most of my plants in a cold, dormant state longer than usual to delay their growth.

There was definitely a negative impact on many of my plants. As for my Plumerias, black tip was evident much more than ever in the past. Also, my 2 largest Plumies started off with swelling of the claws and inflo formation normally, but then they stalled for a very long time. I knew something was up with the roots. Most of the root system in the 5-gal pots had rotted. I'm not concerned about the plants, I repotted and took all the precautions. They will be fine.

Plumeria can tolerate a few months of cold and dark as evidenced by my success for many years. But when this period approaches closer to 4 months of cold dormancy, the plants will not be nearly as healthy.

The plants with black tip have recovered very nicely. Their root systems were still healthy because they were kept in a much more porous mix than my larger plants which were still in an older mix that was not as porous - I was just being lazy and never decided to make the change.

I also wanted to see how much heat and drought a Plumeria can tolerate while dormant. I have one small 'Rainbow Ribbon' plant (3 footer) that I decided to keep dry and very warm in my garage, rather than get into growth in my greenhouse. This plant still has no growth, despite consistent heat into the 80's and 90's, and some direct sun through a window, since May. The stem is perfectly solid, there is no rot, the root system is healthy (I see white roots through the drainage holes). I was always hesitant to keep some of my plants at room temps overwinter for fear of early growth in poor indoor lighting, but maybe as long as they can be kept quite dry and leafless, they may not be interested in growing until some moisture is provided as stimulation.

Obviously different varieties will react differently.

To fellow Plumeria growers in the colder "North":

1) Don't keep your plants cool and dry for more than about 2 months, otherwise the risk of black tip increases.

2) Make sure your potting mix drains exceptionally well. Even pure perlite would work. You can't get any better aeration than that (but it is messy!).

3) A leafless, dormant plant can tolerate warmth and drought pretty well, and is probably safer for the roots and reduces the risk of rot and black tip.

4) An effective overwintering strategy would be to let the plant go leafless in the fall, and leave the plant warm and dry for several months before you introduce the plant to better light, water and fertilizer to kick-off the growing season.

YMMV

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