Garden plant of the moment: Bougainvillea

For an instant sensational appeal, few plants can beat Bougainvilleas. Their luminously vibrant flowers are like a window into a warmer place when our summer skies are grey. The vivid blooms are actually brightly coloured bracts surrounding clusters of tiny white flowers, and although they look exotic, you can grow Bougainvilleas in the UK – you just need to protect them from frost.


Where to grow Bougainvilleas

Bougainvilleas are best grown in a greenhouse or conservatory in a spot that gets at least 5-6 hours of bright indirect light.

Bougainvillea ‘Barbara Karst’ is one of the hardiest varieties available, with stunning magenta-purple flowers all summer long. White and orange Bougainvilleas aren’t as hardy, but will be happy in a conservatory or heated greenhouse.

When planting your Bougainvillea in a pot, use a loam-based compost. Bougainvilleas can be trained as standards or as climbers against a trellis or other support.


How to feed and water Bougainvillea

Bougainvilleas start to grow in early spring. Once leaf buds appear, water your Bougainvillea thoroughly every couple of weeks, letting the compost dry out between waterings. If you live in a hard water area, use rainwater rather than tap water whenever possible.

Around mid-April, start feeding your Bougainvillea weekly with a high-nitrogen feed. Once the bracts start to colour, switch to a high-potash feed. If you’re growing a Bougainvillea under glass (e.g. in a conservatory), the bracts will last longer if you can protect it from direct sunlight at this stage. Once the bracts drop off, switch back to a high-nitrogen feed to encourage a second flush of Bougainvillea in pot flowers.

Flowering stops in early autumn. After this, stop feeding your Bougainvillea and water less often, perhaps once or twice a month. Bougainvilleas can survive winter temperatures of down to 2°C (35°F), although they will drop their leaves once the temperature falls below 10°C (50°F).  


How to prune Bougainvilleas

Prune Bougainvilleas in late winter or early spring before they start to grow, to keep them to the size you want. Tie the shoots back to a trellis or other support framework.  Bougainvilleas are exceptionally thorny, so you’ll need gloves for this!


Common questions about Bougainvilleas

  1. Why is my Bougainvillea dropping its leaves?
    In summer, this is usually due to either over- or under-watering. If the compost is soggy, let it dry out before watering again. If the compost is dry, water thoroughly to soak the roots, then wait until the compost is dry before watering again. Bougainvilleas also drop their leaves if the temperature falls below 10°C (50°F).
  2. Why is my Bougainvillea not flowering?
    To stimulate the plant to produce flowers, stop watering until the leaves start to wilt, then water normally.

There’s nothing quite like a Bougainvillea for filling your home with flamboyant colour, so visit the garden centre and pick your favourite!