Bougainvillea

About Bougainvillea

Bougainvillea is a thorny, scrambling tropical vine or shrub grown for its papery, brightly colored bracts; the true flowers are tiny and white, tucked inside (NC State; UF/IFAS). In frost-free areas it covers fences, walls and arbors and takes heat, drought and salt spray in stride. Elsewhere it's a sun-loving patio, hanging-basket or house plant that can spend winter indoors.

Hardy outdoors only in about zones 9b-10 and other frost-free spots (UF/IFAS, NC State); cold causes dieback and leaf drop. Everywhere else, grow it in a pot and bring it in for winter.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Plant or set out pots in full sun after frost danger has passed; without some direct sun it won't bloom (UF/IFAS). In pots use a fast-draining mix that isn't heavy on peat, since the fine roots rot easily (UF/IFAS ENH 874). To overwinter, bring it in before nights regularly drop below 45 F: cut back small potted plants and keep them in a sunny window, or let big pots go dormant in a cool place that doesn't freeze, never letting the roots dry out completely or stay wet (MU Extension). Days to first bloom aren't documented; nursery plants are usually sold in color.

Soil

Fast-draining sandy or loamy soil that's slightly acidic; keep it on the dry side, and expect yellow leaves from missing micronutrients in alkaline soil (UF/IFAS, NC State).

Use a fast-draining, slightly acidic soil or mix (about pH 5.5-6.0) and avoid peat-heavy mixes that stay wet (UF/IFAS ENH 874).

Feeding

• During active growth in spring and summer: balanced fertilizer, used sparingly. Feed lightly; too much fertilizer, especially nitrogen, gives leaves instead of colorful bracts (UF/IFAS). Follow the label.
• Only if new leaves turn pale or yellow between the veins: Epsom salts (magnesium sulfate) or a micronutrient spray labeled for palms or citrus. UF/IFAS lists 1-2 tsp Epsom salts per gallon as a drench or leaf spray for magnesium shortage; follow the label, since micronutrient sprays can stain concrete and stone.

Overwatering, too much shade, too much fertilizer and heavy late-summer pruning all cut down on blooms (UF/IFAS).

Harvest

Color comes in flushes on new growth through much of the year where it's frost-free, heaviest in winter's short days in Florida; a sunny potted plant can stay colorful for up to about eight weeks (UF/IFAS). Prune after a flush in late winter or early spring (or at the start of the rainy season), not in late summer or early fall, and let the soil get a bit dry between waterings to bring on more bracts (UF/IFAS).

Varieties (19)

Pests to watch for

Aphids

Diseases and problems

Root rot, Iron chlorosis, Magnesium deficiency

In the kitchen

Safety: Grown as an ornamental only. The long, sharp thorns can cut skin, so wear heavy gloves and long sleeves when pruning (UF/IFAS); we found no extension toxicity listing for it.

Pets: Not listed by the ASPCA (no bougainvillea entry); the sharp thorns are the main hazard.