How to grow campsis

What is campsis?

Campsis is a vigorous long-lived climber, also known as the trumpet vine. It puts on a striking floral display in late summer, with large clusters of showy orange-red or yellow blooms. It is fast growing, forming a woody framework after a few years, and is self-clinging, using aerial roots to grip onto vertical surfaces. It flowers best in full sun, in a warm sheltered spot.

How and what to buy

Campsis is widely available all year round, from garden centres and online suppliers, including RHS Plants. Plants are usually in fairly large containers, ready for immediate planting.

There are several species and cultivars, with flowers in various fiery shades. Popular choices include:

• Campsis radicans – with bright orange-red flowers
• Campsis grandiflora – with dark orange-red flowers
• Campsis x tagliabuana 'Madame Galen' – with pink-red flowers
• Campsis radicans f. flava – with deep yellow flowers

These are all deciduous

Deciduous refers to plants (mainly trees and shrubs) that lose their leaves seasonally, usually during autumn. This is a natural process triggered by the season's shorter days and lower temperatures and allows plants to conserve energy during the winter months.

, losing their leaves over winter, and are similarly vigorous, reaching an ultimate height of up to 10m (30ft) after ten years, if given free range. Plants can be pruned annually to keep them within bounds.

Despite looking exotic, campsis is hardy, although it prefers a warm sheltered location with fertile well-drained soil.

To work out if you have the right conditions in your garden, see our guide to assessing your microclimate.

Where to get ideas and advice

Go to RHS Find a Plant and search for 'campsis' to browse photos and plant descriptions, and find out where to buy them.

RHS members can use the free personal gardening coach at My RHS.

Climbers for sunny walls

Guide to climbers and wall shrubs

Where to plant

Plant campsis in a border at the base of a large wall, pergola or other sturdy structure. It can also be planted near a large tree to grow up through it. Campsis is a vigorous climber, so the support must be at least 4m (13ft) high.

Although hardy, campsis needs shelter from cold winds, and full sun in order to ripen the wood so it flowers freely.

It does well in any moderately fertile, moist but well-drained soil.

Campsis can also be grown in a large container against a wall or other robust support. Fill the container with loam-based, peat-free potting compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

, such as John Innes No 2, or multi-purpose compost. Extra grit may be added to improve drainage.

When to plant

Plant campsis between autumn and spring, as long as the ground isn’t frozen or waterlogged

Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted.

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How to plant

Campsis is very easy to plant – see our step-by-step guide to planting climbers.

Watering

Campsis is fairly drought tolerant, but when newly planted or when growing in a container, it should be watered as needed in dry spells. Even well- established plants

Established plants have been in their current location for two or three years and so have well-developed root systems able to support strong growth with healthy foliage and flowers.

will perform better if watered during prolonged droughts.

Tips on recycling and collecting water

Feeding

Campsis generally does well without additional feeding, unless grown in a container.

Container-grown plants can be fed with potassium-rich liquid feed, such as tomato fertiliser, to encourage flowering. Follow the dose rate and frequency recommended on the packet.

How to use fertilisers

How to look after plants in containers

Mulching

Lay a thick layer of mulch

Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings.

, such as garden compost, over the plant's root zone every spring or autumn, to help hold moisture in the soil.

How to use mulch

Caring for older plants

Older plants can grow very large (up to 10m or 30ft high), so are best pruned annually to keep them to a manageable size. Overgrown plants can be cut back hard. See our pruning advice below.

Campsis is a self-clinging climber, using aerial roots along its long stems to grip onto vertical surfaces. Campsis grandiflora, however, is best tied in to supporting wires.

It takes two or three years for a plant to establish a strong woody framework of branches, before it will begin to flower well.

Training a young plant

The aim is to produce a framework of stems from which flowering shoots emerge each year.

After planting, cut back all the stems to 15cm (6in) from the ground to stimulate new growth. Train the strongest of the resulting new shoots to fill the space – see our guide to training and pruning climbers on planting. Always remove weaker shoots.

Pruning an established plant

Once a framework is established, usually in two to three years, 'spur-prune' the sideshoots annually in late winter. This involves cutting back all the sideshoots to within two or three buds of the main stems. Remove any weak growth and cut back damaged stems close to their base.

Renovating an old plant

Hard pruning will reduce flowering, but can be used to renovate an overgrown plant.

Cut back all the shoots to within 30cm (12in) of the base in late winter, then train in the strongest of the resulting new shoots, as for a new plant (see above).

How to sharpen pruning tools

The easiest way to propagate campsis is by layering or by taking cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

– semi-ripe, hardwood or root cuttings.

Rooted suckers that grow from the base can be severed from the parent plant and potted up on their own. Once large enough, they can be transplanted

Moving a plant from one growing position to another, often from a pot to its final spot in the garden.

into the garden.

Campsis can also be grown from seed. Sow in autumn into small pots or trays of peat-free seed compost

Seed compost is a free-draining compost formulated for germinating seed. It often contains a mix of fine materials including sterilised loam, coir, coarse sand or grit. It contains low levels of nutrients, as high levels could damage seedlings.

, then place in a coldframe to germinate and grow. Growing from seed can be a slow process though, as germination

Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light.

can take several months, and plants can then take a few years to reach flowering size.

How to take cuttings from climbers

As campsis is generally such a strong, vigorous plant, it tends to be relatively trouble free. However, low temperatures or dry soil can cause flower buds to be shed. So always grow campsis in a warm sheltered spot and water during dry spells until well established.

Few pests and diseases affect campsis, although you may occasionally spot:

Powdery mildew
Aphids
Mealybugs
Scale insects

Outbreaks rarely need treating on large, well- established plants

Established plants have been in their current location for two or three years and so have well-developed root systems able to support strong growth with healthy foliage and flowers.

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Guide to preventing pests and diseases

How to control pests and diseases without chemicals