If temps drop below 40 degrees it is time to start watching for freezing temperatures!
Plumerias can withstand, once well established, temps down to 32 with some “burn” only, however, younger plants do not fare so well. It is recommended you do the following:
Leave out as weather cools and leaves will drop—the plant goes to sleep and can be stored thusly in a dark closet, basement, or room all winter with no care at all. It is wise though to check once a month and if it looks shriveled, then give it a small drink of water and then do not water again until spring.
Plants which are planted in the ground
You have two choices:
- Dig them up and shake off the excess dirt. Hang them on clotheslines, or, stand them up in buckets and/or lightly packed loosely wadded newspaper around the roots. Store in a warm and protected place—light or no light are not important as either situation is just fine! You can also wrap the roots loosely in newspaper and stand them up as long as the roots do not contact cold surfaces directly. I stand mine up in the corners and sides of my greenhouse next to the ones that are in pots, also being stored dry—see pictures. Some will even put out flowers early—-if they are in a place that gets sunlight. Replant in the Spring when danger of frost is passed and watch in wonder as your plumeria begins to grow once more like it never moved from its place. Just water in well and leave it be until you see leaves forming. You may increase water slowly as more leaves form—be careful to not leave the soil too wet. Fertilize once you have a couple sets of new leaves.
- If you leave them in the ground it is advisable to have large pieces of frost cloth or blankets available to cover in the event of freezing temperatures. You should also get an inexpensive outdoor light fixture and put a floodlight under the tree aiming upwards into the center. For larger trees, you can drape large sheets or blankets over them and use whatever method that does not damage branches to secure them. Please add the light for temps below 30 degrees! DO NOT USE PLASTIC unless you have a solid frame and it will not touch the branches or any remaining leaves as it can damage your plant. Also, the next day when it warms up the plastic will hold too much heat and “cook” your plant unless you can remember to remove it each day. Sheets and fabrics can “breathe” and are therefore better. PLEASE make sure the fabric cannot be blown as to touch and rub against the tips, which is where new flower stalks are produced! If you damage the tips, you may not get any flowers! In spring you can remove covers permanently, replant dug-up plants, and, put pots back outside. Water in once and do not water or fertilize again until you see a few new leaves emerging. Your plants will perform a miracle and suddenly they will be growing like nothing happened!