|I purchased a potted Bougainvillea `Barbara Karst`late last May from Home Depot in Round Lake Illinois. The plant was incredibly beautiful when purchased and stayed beautiful for about 1 month, gradually losing its bright pink flowers. I kept the plant in its original Monrovia plastic container, on my patio where it receives sun most of the day (some morning but mostly afternoon). At this writing, the plant is void of flowers, but green leaves remain. In my quest to perpetuate the pink flowers, I searched the internet(alas I should have contacted Monrovia first) and found advice ranging from Bougainvillea's love water to Bougainvillea's need minimal water. I have actually watered somewhere in between, depending on the air temp.
We're in a drought right now, with frequent sun and hot humid conditions. I placed a slow release fertilizer at soil surface apx. mid June. The fertilizer is a
|Bougainvilleas bloom in a 5-6 weeks cycle and they tend to bloom better if they are kept on the dry side. Perhaps this is because in their native habitate they flower after a rainfall that ends a drought. In any event, provide as much sunshine as possible - the less direct sun, the fewer the blooms. You didn't mention whether or not you'd pruned your bougainvillea. These plants produce flowers on new wood that develops on old wood. You can try pruning it back a bit to force new flowering stems.
Bougainvilleas winter over very nicely indoors if they kept in a cool (57-68 degrees F) and bright location. Reduce watering, and when the foliage drops, do not water at all. Cut the plant back in March and repot it.
Best wishes with your bougainvillea!