How to Grow Bougainvillea in a UK Pot

Bougainvillea brings a taste of Mediterranean summer to a British patio, with sheets of magenta, purple or red colour from summer into autumn. The secret to growing it here is simple: keep it in a pot. It hates frost and cold, wet roots, and a container lets you sidestep both.

Grow it in a snug pot, give it full sun outside in summer and wheel it under glass before the first frost. This guide covers the pot, the position, watering and feeding for colour, pruning and getting it safely through a British winter.

Can you grow bougainvillea in the UK?

Yes, but almost always in a pot that spends winter under cover. Bougainvillea is frost-tender: one frost can kill it, and cold, wet roots rot it. Planted in the ground, it rarely survives a British winter, even in mild coastal gardens.

Treat it as a container plant that summers outdoors and winters in a conservatory, porch or frost-free greenhouse. That way you control its warmth and watering all year.

The colour you see isn’t petals. The real flowers are the tiny cream trumpets in the middle, usually in threes. Around them sit papery, brightly coloured bracts, a type of modified leaf. They hold their colour for weeks, which is why the show lasts so long.

Those tiny cream flowers are the real blooms. The bright, papery bracts around them give bougainvillea its colour.

Which bougainvillea should you buy?

Choose a vigorous, free-flowering variety that colours up well in our shorter summers. These are reliable choices in UK pots and conservatories.

You can buy young plants or larger plants already trained into a standard or a pyramid on canes. A trained plant saves you a couple of years of shaping.

A ready-trained standard gives instant impact on a sunny patio. It still needs to come in before the frosts.

Where to grow bougainvillea

Give bougainvillea the sunniest, warmest spot you have. Under glass, that means a south or west-facing conservatory. Outdoors in summer, it means a sheltered suntrap against a warm wall.

From June to September, stand the pot outside in full sun once all risk of frost has gone. Extra light and fresh air give better colour and sturdier growth. Choose a sheltered spot, as wind tears the papery bracts and dries the pot quickly.

It looks at home with potted olives, pelargoniums and other sun-lovers, and fits a Mediterranean-style garden well. Under glass, it sits happily beside other conservatory plants, though it wants more light than most.

Gardener’s tip: Stand the pot on a wheeled plant caddy from day one. A big bougainvillea in loam-based compost is heavy, and you’ll move it in and out twice a year.

Inside a bright conservatory or greenhouse, bougainvillea gets the warmth and light it loves.

What pot and compost does bougainvillea need?

Use loam-based John Innes No 3 in a pot only a little bigger than the roots. Bougainvillea flowers best when its roots are slightly snug, so a pot that’s too big is a common mistake.

Loam-based compost holds nutrients well, gives weight so a tall plant doesn’t blow over, and drains freely. Mix in some horticultural grit to help drainage, as bougainvillea rots in soggy compost.

Start a young plant in a 20-25cm pot and move up one size at a time. Most mature plants are happy in a 30-45cm pot for years. Repot only when roots fill the pot, every two or three years, in early spring as growth starts.

Move up just one pot size at a time. Snug roots mean more colour.

How to make bougainvillea flower

Give it full sun, water sparingly in summer and feed for flowers. Bougainvillea colours up best when it’s a little on the dry side.

Watering: water well while it is growing in spring. Through summer, let the top of the compost dry out between waterings, then water thoroughly. Constantly wet compost gives lots of leafy growth and little colour. Never let the pot sit in a saucer of water.

Feeding: from spring, use a balanced liquid feed to build healthy growth. Once the bracts start to colour, switch to a high-potash feed such as tomato feed. Potash encourages flowers; too much nitrogen gives leaves.

Light: the more direct sun the better. A plant in a shady corner grows but sulks. Move it into the light and colour follows.

How and when to prune bougainvillea

Prune in late winter or early spring, before new growth begins. Bougainvillea flowers on new growth, so a good prune now gives more flowering shoots later.

Cut last year’s long shoots back to a few buds from the main framework. Take out thin, weak or crossing stems at the same time. In summer, after a flush of colour fades, trim the flowered shoots lightly to encourage another flush.

Always wear thick gloves and long sleeves. Bougainvillea has sharp, hooked thorns. If you are training it up a frame or wall, tie in young shoots while they’re bendy, as older stems snap. It’s much like training a passionflower in a pot: a light frame, regular tying-in and a tidy each spring.

Late winter is pruning time, just as fresh red shoots appear. Thick gloves make the thorns far less painful.

How to overwinter bougainvillea

Bring bougainvillea under cover before the first frost, usually by early October. Keep it frost-free all winter, ideally at around 10°C.

A conservatory, porch, frost-free greenhouse or a cool, bright room all work. Somewhat cooler, it usually drops most of its leaves and rests. That looks alarming but is normal. Don’t throw it out.

Watering is the key winter job. Keep the compost barely moist, watering only occasionally. Cold, wet compost rots the roots and kills more bougainvilleas than cold alone. Stop feeding from autumn until growth starts again.

New shoots usually appear in spring. Then increase watering, start feeding and get ready to move it outside. The guide to overwintering plants covers the same routine for other tender plants.

Move it back outside only when the frosts are over, usually in early June. Harden it off over a week or two first. If a late cold night is forecast, wheel it back in. The guide to protecting plants from frost has quick fixes.

A resting bougainvillea often drops its leaves in a cool porch. Keep it nearly dry and it reshoots in spring.

Bougainvillea pests under glass

Under glass, watch for whitefly, mealybug, aphids and red spider mite, which all love warmth. Check shoot tips and leaf undersides every week.

• Wipe off mealybug with a damp cotton bud.
• Sponge or hose off aphids and whitefly.
• Mist and damp down to raise humidity, which red spider mite dislikes.
• Use yellow sticky traps to spot whitefly early.

For bigger outbreaks, biological controls work well in a conservatory or greenhouse. The greenhouse pest control guide explains the options, or use an approved product for that use, following the label.

Bougainvillea growing calendar

Common mistakes with bougainvillea

1. Overwatering. Wet compost gives leaves, not colour, and rots roots in winter. Let it dry a little between waterings.
2. Too big a pot. Lots of root room means leafy growth. Keep it snug.
3. Too little sun. A shady spot gives a green plant. Give it the sunniest place you have.
4. Leaving it out too late. One frost can kill it. Bring it in by early October.
5. Pruning at the wrong time. Heavy cuts in summer remove flowering shoots. Do the main prune in late winter.

More tender plants for pots

If you love bougainvillea, try another tender climber with a similar routine. Mandevilla has big trumpet flowers all summer, and an olive tree makes a great potted partner on a sunny patio. Browse more growing guides for your next project.

Summer on a sheltered patio. Come October, this pot goes back under glass until the frosts are over.

Frequently asked questions

Is bougainvillea hardy in the UK?

No, bougainvillea is frost-tender and not hardy here. Grow it in a pot, stand it outside in summer and move it under glass before the first frost. Even mild coastal gardens can lose a planted-out one in a cold winter.

What temperature can bougainvillea tolerate?

It must be kept frost-free, ideally around 10°C in winter. Cooler than that, it usually drops its leaves and rests. It can survive if the compost is kept nearly dry, but frost kills it.

Why won’t my bougainvillea flower?

Usually too much water, too little sun or too much nitrogen. Give it full sun, let the compost dry a little between waterings and switch to a high-potash feed in summer.

Why is my bougainvillea dropping its leaves?

In winter, leaf drop is normal when it gets cool. It rests and releafs in spring. In summer, leaf drop usually means a cold draught, a recent move or very dry roots.

When should I prune bougainvillea?

Prune in late winter or early spring, before new growth starts. Cut last year’s long shoots back to a few buds. Lightly trim flowered shoots in summer for another flush. Wear thick gloves for the thorns.

Can bougainvillea survive winter outside in the UK?

Rarely, so it is best not to risk it. Frost and winter wet soon kill it outdoors. Keep it in a pot you can wheel under cover from early autumn to late spring.

How big a pot does bougainvillea need?

A snug pot, usually 30-45cm across for a mature plant. It flowers best with its roots a little restricted, so pot on only when roots fill the pot, one size up at a time.