The bougainvillea vine, named after the 18th century Admiral Louis de Bougainvillea who discovered it, is a tropical plant grown in USDA hardiness zones 9b through 11. The exceptionally hardy plant can be grown both in pots and in the ground. If your bougainvillea exhibits problematic signs, such as a lack of blossoms or the dropping of leaves, troubleshoot it to help pinpoint the problem and restore the plant to its full health.
Increase the amount of sun your bougainvillea plant is receiving if it isn't blooming or if it's dropping its leaves. The plant requires a minimum of six hours of direct sunlight per day. If it's in a pot, move the pot. If it's in the ground, prune back surrounding trees or shrubs to open up the space around the plant and allow in more sunlight.
Feed the bougainvillea. The plants have high nutrient needs, and poor blooming or stunted growth may occur if these needs are not met. Use a standard water-soluble 20-20-20 garden fertilizer and apply it once a month according to the fertilizer label's guidelines, since potency varies by product.
Time your pruning if you like to shape your bougainvillea plant. Only prune during the spring growing season. Pruning after this will cut off the stems upon which the bougainvillea plant produces blooms, thereby minimizing your plant's flowering.
Inspect the bougainvillea plant for aphids or the cabbage looper (Trichoplusia ni) moth. These are one of the few pests that may occasionally show up on your plant and may cause visible signs of stress, like wilting or drooping of the bougainvillea's branches. If you notice such pests, spray your plant with a standard insecticidal soap to quickly resolve the problem.