A bougainvillea (Bougainvillea glabra) plant is a blooming machine that produces blooms almost year-round in mild climates. However, even this hardy, proficient blooming plant does have a few nemeses that can cause it to stop producing blooms.
Not enough sunlight and too much water are the most common causes of a bougainvillea not blooming, but there are also other culprits. Let’s look at some of the common causes and practical fixes so you can get your plant blooming again.
Not Enough Sunlight
Bougainvillea is a sun-lover and grows best in full sun. The plant will thrive in a location that receives at least 6-hours of direct sunlight each day.
If your bougainvillea has bloomed in the past but suddenly stopped blooming, check for tree branches that may have grown over them and are now blocking the sun from shining on the plants.
Too Much Water
Bougainvillea is native to very arid climates and does not need much water to survive. Water it only when the top 2-inches (5 cm) of the soil feel dry to the touch. Too much water encourages root rot and discourages blooms.
Overfeeding
If your bougainvillea has plenty of healthy green foliage but no blooms, you probably overfed it.
Plant food that is rich in nitrogen encourages bougainvillea to produce lots of top growth foliage but no flower buds.
Encourage bougainvillea to develop buds and produce blooms by feeding it less nitrogen-rich food and more phosphate and potassium-rich foods, like fish emulsion, kelp, or bone meal. Add nitrogen-rich plant food only when the plant foliage begins to look less green than usual.
Over-Pruning
Bougainvillea is a wild, native plant and does not enjoy being pruned. Over-pruning will significantly reduce the number of blooms your bougainvillea produces, so be gentle with the pruning shears.
If the plant needs to be pruned, do it immediately after blooms begin to fade. If you only have a small space, plant a dwarf bougainvillea so you won’t have to prune it.
Re-Potting
Bougainvillea is a hardy plant that thrives on very little water and lots of neglect. The plant grows better when it’s slightly root-bound and it hates being re-potted.
This is why potted bougainvillea produce more blooms than plants grown outdoor in the landscape. For the most blooms, bury a potted bougainvillea in the landscape and never re-pot a container-grown bougainvillea.