Most people cut it way back in the fall, and keep it in a garage, basement, or porch (as long as it is not too cold) for the season. Although bougainvillea shrubs are sturdy plants that often withstand extensive abuse without showing signs of trauma, they do have a limit to the amount of stress they can tolerate and continue thriving. We have gone away in past summers and came back to a totally thriving Mandevilla. My bougainvillea got frosted this year. Even with natural predators, bougainvillea loopers can sometimes multiply faster than the predators can eat. Hope this helps. All of our plants did great, including hydrangeas, Jasmine, vincas, and a potted bougainvillea, etc., but the Mandevilla did terribly. It had no leaves or blooms and they felt it was dying and gave up on it. A dying bougainvillea is often due to over watering, slow draining soils and cold temperatures. See how my Bougainvillea glabra looks in the middle of winter: The other reason why yellow leaves fall off of Bougainvilleas in winter is due to a prolonged dry spell. Bougainvillea bracts are the specialised pink leaves with the delicate flowering in between. Why is My Bougainvillea Dying? "Why won't my bougainvillea bloom?," is perhaps the most frequently asked question among gardeners. I see yours are outside, so try cutting them back and check the trunk for bright light green new growth. The pink one died at some point, but the red survived. My bougainvillea seems to be wilting (not drying) and turning black. This is the first year this happened. This bougainvillea has been here since the last 1.5 years and has done well in growing quickly (too quickly), but has bloomed sparsely at the tips. I personally water my potted bougainvilleas once every week during the Spring and Summer and find this is the ideal balance to meet the moisture requirements and also stimulate blooms. Bougainvillea loopers have many natural predators, such as birds and omnivorous animals. Culture - Bougainvilleas grow in USDA hardiness zones 9 to11; however, a majority of the species are confined to only the warmest zones. So my yard went through 6 years of complete neglect after my grandma died... what ever was left has managed to survive in clay soil, and SoCal's weather for six years. Attracting these animals to your yard can help keep the bougainvillea looper caterpillar population under control. I am from the Bay area, zone 9B. The last few winters haven’t been too cold here but they have been dry. A dying bougainvillea is often due to over watering, slow draining soils and cold temperatures. And give it a good drink also. I thought I’d lost it but I cut it back and it’s got lots of new growth. They do not tolerate frost. Select a species well-adapted to your particular USDA hardiness zones. I would think that in your climate, you could overwinter a bougainvillea safely outside without fear of freezing to death. Before she died my grandma had planted two bougainvillea's, one red, and one light pink and white. In my experience, bougainvillea thrives if given a cool dormant period. Bougainvillea, many say, color best when somewhat pot-bound. I was reading in a blog, not long ago, where someone had purchased a bougainvillea. It became what I refer to as "sticky". It is potted and in an Unheated sun room. If you fear for your shrub, tell if your bougainvillea is dead by assessing the foliage of the plant. Why is My Bougainvillea Dying? Frost can cause portions of the plant, or the entire plant, to wither and turn black.