|I have a pot [24"h x18"w] with a bouganvilla in it. It grows in a covered atrium in the front of my home in the summer. As soon as freezing weather sets in in the fall, I moved it into my greenhouse [16'L x 8'w x 9' H] which is built as a glass leanto against the west side of my home. The bouganvilla does well until about this time each year. It begins to grow and bloom as soon as it is placed in the greenhouse and then as I said about this time each year it dies. It just goes downhill after the middle of December. I have a natural gas furnace in the greenhouse and it has a programable thermostat. I keep it 60 degrees in the day and let the night time temperature fall to 40 at night. I have two other large pots with rose trees in them and they do just marvelously while the bouganvilla wanes. Can you tell me why?
|This is not so unusual for this tropical plant. It often goes dormant during the winter so I suspect your bougainvillea is defoliating in protest of the cool temperatures combined with the shorter days. If you trim it back hard right after blooming and allow it to rest during the winter, it should come back for you as long as it has not gotten so cold it stressed thoroughly and died. (It would be not be that severely stressed at 40 F, but perhaps you might try a min-max thermometer to make sure it is not colder than that at night.) Ideally, you would want to keep it between 50 and 65 during the winter and water it only lightly since it is not in active growth. The roses on the other hand should be very happy in the temperature range you described -- they are far more cold tolerant plants.|