Expert: C.L. Fornari - 5/3/2009

Question
Hi, I live in Katy, Texas and have 5 potted bougainvilleas that do very well in terms of maintaining constant blooms.  I have planted two seperate bougainvilleas in the ground last spring (2008) which have yet bloom.  They are definately growing and I don't treat these two planted in the ground any differently than those I have potted.  But I can't seem to get them to bloom.  Any suggestions?

Answer
Mary,
Frequently Bougainvillea bloom better in pots because they are root bound and that slight stress makes them bloom better. Be sure that your plants that are in the ground are in full sun - Bougainvillea must be in full sun (at least 6 hours including the noon hour) in order to bloom. Be sure that they are not getting too much nitrogen from either fertilizers high in nitrogen that you're applying to the plant or from lawn fertilizer that might be applied near the plant. Nitrogen encourages more leaf growth.  Also, be sure that the plant isn't being kept constantly moist - although they will grow well with constant moisture, the drying out between waterings provides the stress that can stimulate the plant to bloom. Sometimes pruning helps too, as Bougainvilleas bloom on new growth, and pruning can both provide that stress and stimulate new growth that will flower.  

This website has one man's experience - he's also a Texas gardener:  http://www.texasgardener.com/pastissues/julaug04/hungry.html

So, bottom line is be sure it's in sun, don't fertilize any more if you already have, let the plant go dry between waterings, and prune it back some now.  

I hope that helps!
C.L.