Tips on Bougainvillea Culture

(Weeder's Digest October 2002)

Bougainvillea sp.     Nyctaginaceae  

1.  SPECIES:
A. Bougainvillea spectabilis
Thorns are strong, woody, hairy, slightly curved.
Leaves are ovate to rounded, leathery and hairy underneath.
Dense plant; branches short and close together.
Inflorescences are multiple; terminal
Flowering in dry weather or cool dry weather
Bracts large, ovate; color rose, rusty red, purple
Flowers are cream, narrow tube and hairy
B.  Bougainvillea glabra
Thorns are short, thin, and curved at tips
Leaves elliptical, wide in middle, hairy
Branches close together; flowers along the canes
Flowering nearly continuous
Bracts are pointed, triangular and vary in size; nearly always white or nearly so, shading to mauve and purple
C.  Bougainvillea peruviana
Spines many, thin when young, later curved
Leaves thin, smooth, ovate with acute tip; leaf stems long
Branching loose and open
Flowers after new vegetative growth; responds to dry weather
Bracts are small, rounded, delicate, crinkly; pale magenta to pink
Flowers are tubular, slender, smooth; yellowish
Most of the bougainvilleas we choose for pot culture are hybrids or cultivars of these species.
     2.  POT CULTURE
A.  Soil Mix
Needs to be rich with peat and good compost; it should not be compacted.  Good quality commercial mix is suitable with perhaps the addition of extra vermiculite to help retain moisture and some additional peat.  To this add time-release fertilizer.  Make sure the mix is thoroughly mixed and completely moistened before use.  Staking may be desirable.  The addition of a mulch is desirable as a topping to help retain the mix and moisture.
B.  Fertilizer
Bougainvilleas are heavy feeders.  They tolerate a monthly addition of fertilizer as a top dressing, one that is high in potash (K), with the addition of a quarter tsp. of Epsom salts (magnesium sulphate).  One may also fertilize with a foliar spray every 7 to 10 days.  Always water after adding fertilizer.
C.  Watering
Potted bougainvilleas usually need daily watering; if it is very hot, they may need additional spraying.  It is necessary to thoroughly soak the mix so that water runs out the drain holes.
D. Pruning
Shape and prune plants after flowering.  Remove spent flowers.  Snip branch tips back to a leaf node.  Flowering is on new leaf growth.  Remove twiggy growth.  If the pruning of several bougainvillea pots is done on a staggered basis, there should always be a pot of bougainvillea in bloom.  It is permissible to remove the roots from drainage holes.
With a regular schedule of pruning, fertilizing, and watering, a bougainvillea plant usually will bloom for six weeks.  It takes four to six weeks to bloom after pruning.