Bougainvilleas are vigorous tropical vines that bloom in a range of vibrant, jewel-toned hues that create cascades of eye-popping color. With woody vines growing up to 40’ long, bougainvilleas put on a spectacular show when in full bloom.
As versatile as they are beautiful, bougainvilleas are often trained to grow on trellises, arches, and against walls. They’re at home draping over stone walls and adorning planters — even hanging baskets! They can also be pruned to maintain a shrubby shape and planted in rows to create a hedge. Most varieties have sharp thorns though there are some thornless varieties.
Native to eastern South America, the plants are perennial in frost-free climates and generally bloom for at least four to six weeks in shades of magenta, red, orange, pink, yellow, and white. The papery “flowers” are, botanically speaking, modified leaves called bracts that surround tiny white flowers in the center. The vines are often evergreen, though the plant may drop its leaves during prolonged dry spells, resuming growth when watered. Overall, these reliable plants are drought-tolerant, resistant to pests and diseases, and easy to grow.
There are hundreds of varieties, most of which are hybrids created by crossing the numerous Bougainvillea species. In regions near the equator, they’ll flower nearly year-round. Elsewhere, they typically bloom for four to six weeks, usually in spring and fall when the day length is about 12 hours.
Left on their own, the vigorous vines will ramble over the ground or cascade over walls. Although the plants can “climb” using their curved thorns, they are best trained to a trellis or other support by tying the vines with soft plant ties or strips of fabric.
Growing Zones for Bougainvilleas
Bougainvilleas are perennial in USDA Hardiness Zones 9-11. In colder regions, they can be grown as annuals or overwintered indoors. Although established vines can withstand a light frost, the plants won’t tolerate a hard freeze.
Choosing a Site to Grow Bougainvilleas
Bougainvilleas love heat and sun, making them an ideal choice for south-facing walls where they’ll get at least 6 hours of sun per day. They require well-drained soil that is slightly acidic.
Keep in mind that most varieties have sharp thorns, making them unsuitable for areas with foot traffic. Plan ahead for the vigorous vines by erecting a support at planting time. Wooden and metal trellises and wire grids are good choices. Dwarf varieties produce vines from 3’ to 6’ long and are suitable for planters and hanging baskets.
Planting Instructions for Bougainvilleas
Loosen soil to a depth of at least 12” and mix in some compost and/or slow-release fertilizer prior to planting. Handle young plants carefully to avoid damaging the fragile roots. Set the plant at the same depth as it was in its original container. Install your trellis or other support at planting time. Apply a thin layer of organic mulch, such as pine straw, keeping it a few inches from plant stems to avoid rot. Water plants as needed during their first growing season to keep the soil slightly moist but not saturated. The plants will grow slowly at first as they establish their root systems and may produce few flowers the first year; however, in season two and beyond you’ll be rewarded with stunning blooms for years to come.
Fertilizer for Bougainvilleas
Bougainvilleas need regular fertilizing to support vigorous growth and bountiful blooms. Apply a thin layer of compost or a granular fertilizer to the soil beneath the plants each spring. Avoid over-fertilizing, especially with nitrogen, which will encourage lots of foliage at the expense of flowers.
Bougainvillea Pests and Problems
Bougainvilleas are generally pest- and disease-free. Occasionally, aphids and mites will attack the foliage; these can be controlled with insecticidal soap. Avoid overwatering to discourage root rot.
Ongoing Care for Bougainvilleas
Once mature, bougainvilleas are relatively tolerant of drought. Once plants are established, water in-ground plants thoroughly every three weeks or so. Container-grown plants will need more frequent watering.
Left unpruned, the vines can become rampant and overwhelm their supports, so keep their grown in check with regular pruning. The plants bloom on new wood, so you can prune the plants in late fall or very early spring to encourage a flush of new growth. You can also prune them back after they’re finished flowering. You can do light maintenance pruning, such as removing dead wood or cutting back errant vines, at any time. Wear sturdy gloves; some people get a rash from contact with the foliage, and most varieties have sharp thorns.
In cold climates, you can bring potted plants indoors for the winter. Place them in a sunny window and reduce watering to avoid root rot and allow the plants to rest.