Bougainvillea Not Blooming: How To Get Bougainvillea To Flower

Bougainvillea not blooming
(Image credit: Alamy)

As beautiful as they are the in garden or landscape, getting blooms on bougainvillea can be a difficult task because of the way most gardeners think about their plants. 

Plants, after all, need careful, dedicated care, so no flowers on bougainvillea must mean that they're not getting enough food, water, or light. Shouldn't it? A bougainvillea not blooming is a problem that's easy to overcome, provided you think differently about your plants.

How to Get Bougainvillea to Flower

“Why doesn't my bougainvillea bloom?” It's a common question that growers everywhere ask about the gorgeous plants they brought home from the nursery, when they find the blooms stop coming shortly after the plant landed in its new spot in the garden. 

The problem with bougainvillea is that they're tough plants, hardy to the point of almost being weeds. That being said, they need to be cared for like weeds if you're to find success with them. They need to be neglected to within an inch of their lives. 

There are several errors that growers tend to make that interfere with bougainvillea flower formation, including: 

Overwatering

Being the hardy plants they are, bougainvillea don't need much water. Like cactus, your bougainvillea is actually native to very arid conditions so water it only when the top 2 inches (5 cm.) of the soil feels dry to the touch. More than that and you'll encourage root rot and discourage blooms. 

Overfeeding

When you find your bougainvillea has lots of gorgeous green growth and no blooms, it's probably because of an excessive amount of nitrogen fertilizer. Like other plants, too much nitrogen encourages bougainvillea to add lots of vegetative parts like leaves and stems at the expense of buds. If you want blooms and your plant looks healthy, focus your efforts on supplementing phosphate and potassium, adding nitrogen only when your plant's leaves start to look slightly less green than usual. 

Over Pruning

Heavy pruning of bougainvillea will seriously reduce the amount of blooms your bougainvillea produces, so if you must trim, do so carefully. It's recommended that you only trim right after a bloom if you trim at all. Again, being wild plants, pruning isn't really in their plans, so if you're trimming just to keep your plant small, you might as well replace it with a dwarf variety.

Repotting

Again, your bougainvillea thrives on neglect, including being allowed to become root bound. This is why landscape bougainvillea often doesn't bloom as rigorously or as frequently as those planted in pots. Some growers choose to plant their bougainvilleas in pots buried in the ground, which works to marry the concept of root binding with landscape integration.

Kristi Waterworth
Writer

Kristi Waterworth was a regular contributor to Gardening Know How for many years, answering countless queries on plant pests and diseases.