Light:

Full sun (a south window).

Temperature:

Maintain temperature above 50°; 60° in winter if active growth is desired.

Humidity:

It’s preferable to grow them at 50% or higher; however, they can tolerate lower levels with no harm.

Watering:

Bring the soil to visual dryness between waterings.  The best flowering occurs when the plants are brought to a slight wilt between waterings.

Fertilizer:

Fertilize with a balanced soluble fertilizer i.e. 15-15-15 every two weeks at 1/2 tsp./gallon.  Reduce the frequency during the winter months, especially under cool temperatures.

Pruning:

They can be pruned hard if growth is excessive.  The best time is right after a flowering cycle is completed.  On vining varieties, the selective pruning of stems to thin or reduce the size of the plant can maintain a flowering specimen.

Insects and Disease:

They have susceptibility to aphids and at times mealy bug.  They have little trouble with disease.

Comments:

Bougainvillea are easy to grow and flower if grown under maximum light and stressed with dryness.  The increase and decrease in day length stimulates bud formation, which causes them to go into seasonal blooming cycles.  However, under high light and dryness most varieties will stay in bloom continuously.  They can be wintered over in basements or other cool and lower light areas.  Under these conditions they go into a dormancy and defoliate.  Occasional watering is needed until they start to grow again in the spring where they once again need to be moved into high light.