Bougainvillea in the Czech Republic: growing in a container, flowering, pruning and overwintering

In brief: Bougainvillea is grown in a container in the Czech Republic: summer outdoors in full sun, winter in the light at roughly 10 °C with reduced watering. It flowers on new shoots, so it is pruned at the end of winter. It is not the flowers that are coloured, but the bracts. During growth it wants plenty of water and feed, in winter almost dry.

Anyone who has seen bougainvillea on a wall in the Mediterranean wants to have it at home too. In our climate it can be done, only differently: as a large plant in a container that spends the summer on a terrace and the winter in a cool bright room. The most common disappointment is that the plant grows but does not flower. Almost always the cause is too little sun, a warm winter or pruning at the wrong time.

The guide is built as a calendar, because with bougainvillea what matters most is what you do in which month.

Bracts, not flowers: what actually flowers

Bougainvillea belongs to the four-o'clock family and comes from South America. It is a climbing shrub with thorns, which in the wild leans on surrounding plants. The deep violet, pink, red, orange or white "flowers" are in fact bracts, papery leaves surrounding tiny cream tubular flowers. The bracts last on the plant for several weeks, which is why bougainvillea appears to flower for so long.

A year with bougainvillea in the Czech Republic

Container, substrate and repotting

Bougainvillea needs a free-draining but nutritious substrate. A loamy substrate to which you mix perlite or coarse sand in a ratio of roughly 3 : 1 works best. A purely peat-based substrate stays wet for a long time in winter and in the cold the roots rot. Put a drainage layer at the bottom of the container and never leave water standing in the saucer; this is explained in more detail in the article drainage in a flower pot.

Slightly cramped roots rather encourage flowering. So repot only when the roots grow out through the holes, and always in spring before growth begins, only into a container 3–5 cm larger. The roots are delicate, so do not break up the root ball. The repotting method is described in the article repotting houseplants.

How to get bougainvillea to flower

1. Give it as much sun as possible. A south-facing terrace or wall, outdoors in summer. Behind a window inside a flat it rarely flowers.
2. Do not overwinter it in warmth. A cooler winter around 10 °C with good ventilation helps the plant set bracts.
3. Prune at the right time. It flowers on this year's shoots. A hard cut just before sprouting and shortening after flowering promote new flowering shoots.
4. Feed according to the phase. In spring and at the beginning of summer once a week with a liquid fertiliser with a higher nitrogen content; as soon as coloured bracts show, switch to a fertiliser with a higher potassium content, such as is used for flowering plants.
5. Do not overwater. Let the substrate dry slightly between waterings. A permanently wet bougainvillea grows into leaves.
6. Shorten it after the first flowering. When the bracts fall, shorten the spent shoots by roughly half and return to the nitrogen fertiliser. It then often sets a second wave.

Pruning and shaping

Make the main cut at the end of winter or the beginning of spring, just before the plant starts to sprout. Shorten last year's side shoots to 2–3 buds and remove weak, crossing and dry branches. Long main shoots can be tied to a trellis or an arch; bougainvillea does not climb by itself, it only leans on its thorns.

In a container it can also be trained as a shrub or a standard. Wear sturdy gloves with every cut, as the thorns are sharp and wounds easily become inflamed. You can find inspiration on training climbing plants along a support in the article climbing plants and a vertical garden.

Overwintering: light and cool

Bougainvillea does not tolerate frost. Before the first autumn frost move it indoors to the brightest place you have: a conservatory, a cool veranda, a bright staircase or an unheated room with a large window. Around 10 °C is ideal. Briefly it also tolerates a drop to 4 °C if the substrate is rather dry.

From November water only occasionally but thoroughly, and let the substrate dry out between waterings. In the cold, at 10 °C and below, the plant drops some leaves, which is normal. In a warm living room it also survives winter, but it is often attacked by pests and flowers more weakly the next year. General rules for overwintering container plants can be found in the article overwintering houseplants.

Pests in winter quarters

Under cover, in dry and warm air, the following most often appear on bougainvillea:

• spider mites – fine pale stippling of the leaves and webbing,
• whiteflies – tiny white flies that take off when the plant is moved,
• mealybugs and scale insects – white tufts or brown shields on the shoots,
• aphids – on soft spring shoots.

Check the plant at every watering, especially the undersides of the leaves. How to recognise and deal with the individual pests is described in the article whiteflies, aphids and spider mites. After moving outdoors into the sun and fresh air the problems usually recede quickly.

Thorns, children and animals

Bougainvillea is not listed in the ASPCA database of poisonous plants and is not regarded as a poisonous plant here. The main risk is mechanical: long sharp thorns can injure hands, paws and noses, and some people tolerate the sap less well on the skin. Place the container away from where small children play and where a dog walks, and use gloves when pruning.

Frequently asked questions

How do I overwinter bougainvillea?

In the light in a cool room, ideally around 10 °C. From November water only occasionally and thoroughly, and do not feed. Some leaves may fall; in spring the plant sprouts again.

Why does bougainvillea not flower?

Most often it has too little sun, overwintered in warmth, was overwatered or fed only nitrogen. Full sun outdoors, a cool winter, pruning at the end of winter and, once the bracts colour, a potassium fertiliser help.

When should I prune bougainvillea?

The main cut at the end of winter, just before sprouting. After flowering, when the bracts fall, you can shorten the spent shoots by roughly half to promote further flowering.

Can bougainvillea stay outdoors over winter?

Not in the Czech Republic. Frost damages or destroys it. Move it indoors before the first frost, usually in October.

Is bougainvillea poisonous to cats?

It is not listed in the ASPCA database of poisonous plants. The risk is mainly the sharp thorns, which may injure an animal.

Why is my bougainvillea dropping leaves?

In winter, in the cold, this is normal. In summer the cause is often a sudden change of position, overwatering or, conversely, the substrate drying out completely.

Recommended products

• Gramoflor premium perlite, 100 l – for the bougainvillea substrate, so that it does not hold excess water in winter.
• FERRO metal plant trellis 0.6 × 1.5 m – a support for tying in long shoots in a container or against a wall.
• Kapka for Geraniums 500 ml – a liquid fertiliser for flowering plants in the phase when the bracts are colouring.
• Houseplant fertiliser 1 l – for the spring growth phase before flowering.
• Xcellent garden secateurs, large – for spring pruning and shortening after flowering.

Sources

• Royal Horticultural Society: How to grow bougainvillea
• Royal Horticultural Society: Glasshouse red spider mite

Updated: 27 September 2026