If there's one plant that loves our summer, it's the bougainvillea. The hotter it gets, the better they get, or so it seems.
Actually, bougainvillea blooms best on days that are short on daylight.
But that's not really what this week's article is about. Instead, it's about making the bougainvillea (or "the bogey," as I'll call it from here on) bloom better.
The question I get consistently on the GardenLine radio program is "my bogey is growing well, and looks healthy and green, but what can I do to make it bloom better?"
The answer is (and you lazy gardeners are going to love this) to torture it! Make it suffer!!
First, when we talk about bogeys "blooming," it's sort of a misnomer. The beautiful pink/red/orange color isn't a bloom at all ... it's a modified bract, sort of like a poinsettia's. The actual bloom, once you get the bracts, is the tiny tube with an inconspicuous white/yellow flower on the end. But to make a bogey "bloom" better, we need to apply some stress. And we can do that in a couple ways.
If the bogey is in a container, it should be deprived of water to the point at which it wilts pathetically. Once you have mercifully decided it has wilted enough, you can water it and keep it well watered from that point on. The stress, along with some appropriate food and some selective pinching back of longer branches, forces the modification of the bracts.
With both stressing methods, it's essential to feed the bogeys at least once a month with something like a hibiscus food. Hibiscus foods are normally higher in nitrogen and potassium than phosphorous (the middle number), and that's what we want, because we aren't trying to make it "bloom" the way we do with flowers.
Containerized plants actually like water-soluble plant food better, and there are not a lot of water-soluble hibiscus foods. I'm only aware of Carl Pool's Hibiscus Food and the plant food of the Space City Chapter of the Hibiscus Society, which is sold exclusively in the Houston area. However, you can use simple 1-1-1 water-soluble plant food for containerized bogeys with confidence.
The more commonly found granular hibiscus foods are safe to use on all in-ground bogeys. One very specific bogey food ... Nelson's Nutri Star for Bougainvillea from the makers of Color Star ... can also be used on containerized bogeys. The beauty of the Nelson's product is that it only needs to be applied every two months — all the others need to be used monthly for optimum results.
One more note: In most cases, bogeys actually don't need the best-of-the-best soil. That doesn't mean you can use peat-based soil, which I abhor. But the more loam or clay the better. You'll often see the best looking bogeys in rocky but mineral-rich soils. Think of the Hawaiian islands or resorts along Mexico's rocky shoreline. In fact, some of the best I've ever seen were in a combination of crushed granite and volcanic rock on the isle of Crete in the Mediterranean!