Problems with Bougainvilleas
Bougainvilleas are tropical woody vines that flower abundantly during the summer months. The plant was named for French navigator Louis A. de Bougainville during the 18th century after he found the plant in Brazil and carried some of it back with him to Europe. These colorful, sun-loving evergreens require soil with a pH of at least 6.0. Bougainvilleas produce a light, sweet fragrance. They can be propagated easily from cuttings during its growing season.
Fungi and Bacterial Diseases
Bougainvilleas can be affected by fungal and bacterial leaf spot diseases. Young foliage can develop rust-colored leaf spots, which will eventually kill the leaves. This usually occurs when the plant is living in damp, humid conditions. Other similar diseases can cause yellowing of leaves, which if left untreated, can cause the plant to lose its leaves.
The best way to prevent diseases from occurring in bougainvillea is to keep the plant in a dry location and prune branches that overlap to assure adequate air circulation.
Bougainvilleas are rarely bothered by pests if they receive the proper sunlight and if their soil has good drainage. Wet conditions will draw pests, including caterpillars, mites, aphids, moths, flies, beetles, wasps, scale insects, spider mites and whiteflies. Any of these insects can damage the bougainvillea.
To exterminate pests, mix a cup of vegetable oil with a tablespoon of liquid dishwashing liquid; then add one-third cup of the mixture to a quart of warm water. Spray the plant completely and repeat as necessary.
To encourage profuse flowering, bougainvilleas require at least five hours of direct sun each day. They will live indoors, but will rarely bloom. For the best results, plant your bougainvillea in an outdoor spot that receives full afternoon sun.
Bougainvilleas thrive in temperatures ranging between 60 and 85 degrees Fahrenheit. Temperatures consistently below 60 F will thwart growth, and frosty conditions will cause the plant to lose its leaves and bracts. The plant will probably come back if the frost is not too severe and does not continue for a lengthy period. Move the bougainvillea indoors during cooler months.
Bougainvilleas require external fertilizing to encourage growth and flowering, but too much fertilizer can damage the plant. Choose a time-release fertilizer that contains a high level of phosphorus, plus iron and magnesium. Follow the directions carefully, and apply after watering the plant. Fertilizing when the soil is dry can cause the plant to burn.
Prune your bougainvillea any time it needs it. Pruning will not impact flowering. Pinching the ends will encourage new growth below the cut, which will keep it from becoming straggly.
Hard prune the plant before winter, after blooming has ceased. This will encourage new growth during the spring. And if you plan to move your bougainvillea indoors for the winter, this pruning will make it easier to manage the vines in your home. Expect the plant to lose its leaves and experience a period of dormancy indoors. The bougainvillea requires less water during this time.