In the Garden:
Northern California Coastal & Inland Valleys
Providing color for months is what bougainvillea does best.
I have had the honor to grow the world's most exquisite bougainvillea, so I fancy myself, if not an expert, at least someone who knows what she is talking about. Forget everything you have heard about bougainvillea being drought tolerant. It's not. The more water it receives in sandy, well-drained soil, the better it will bloom for you.
My pride and joy was a 'San Diego Red' variety which was growing on the entertainment patio at the headquarters of Sunset magazine in Menlo Park. It had a semiprotected location against an adobe wall and the required sandy soil and south-facing exposure. It lived in a smallish bed with two citrus trees -- a kumquat and a Dancy tangerine -- that had to be kept moist at all times. I see now that Sunset has changed their recommendation in the New Western Garden Book regarding the watering requirements for this plant. But back then my boss kept telling me not to water the bougainvillea, but when I cut back on water, the plant dropped flowers like crazy. I have always been a bit sneaky and didn't feel a bit guilty about running the hose for a few extra minutes around the roots.
The plant received whatever kind of fertilizer I had on hand. I found the bougainvillea to be a heavy feeder that sucks up every bit of fertilizer that I could throw at it. I gave it a continuous supply of slow-release 14-14-14 throughout the growing period supplemented with bimonthly applications of whatever I happened to be using, sometimes 22-14-14 and sometimes 15-30-15. I never saw the least bit of burn on the foliage from excess fertilizer.
My 'San Diego Red' survived the Big Freeze of 1989 only because I covered it with moving blankets. Bougainvillea is native to the tropics and is damaged by temperatures below freezing. The colder it gets, the more you need to protect the plant. A thick layer of mulch will protect the roots from freezing during those really cold spells. I was lucky enough to have outdoor lighting set up under the plant, and the heat from the lights under the moving blankets was a major contributing factor in its survival, I'm sure.
One thing I did learn is that bougainvillea has the most delicate root system of any plant. Always cut the nursery pot away from the rootball rather than tipping it out of the container to avoid damaging the roots. It goes without saying that you should never, ever loosen the rootball of a bougainvillea at planting time. Set it very carefully into the prepared hole so the top 1 inch of the rootball is above the surface of the soil to allow for adequate drainage. If you do happen to damage the roots, hold off on fertilizer until you begin to see new foliage growth.
Bougainvillea is extremely vigorous and fast growing. Pruning should be done during the growing season to remove those long stringers that will head for the moon if given the chance. Beware of the thorns! Wear heavy gloves. Provide support in the form of sturdy wires or a permanent trellis.
If you have a protected, sunny, south-facing wall, you have the right environment. Nothing adds more color to a drab wall than a bougainvillea. Remember, more food and more water makes more flowers!
Care to share your gardening thoughts, insights, triumphs, or disappointments with your fellow gardening enthusiasts? Join the lively discussions on our FaceBook page and receive free daily tips!