Climbing plants undoubtedly add charm to a property. Many feel climbers allowed to grow up a home forms a natural link between a garden and a home - in the words of RSPB “bringing life to your dead vertical surfaces”. Others simply enjoy the fact that they can decorate a plain-looking wall or mask an eyesore. There are a wide variety of climbing plants to choose from. Some, such as Wisteria, provide a vibrant pop of colour whilst in bloom; others, such Common Ivy, add a covering of foliage throughout the year.

However, many homeowners or homebuyers are hesitant about potential damage from climbing plants, as well as managing their growth. Certainly, some varieties have a bad reputation for causing structural damage, ruining rendering or blocking gutters, damp and pest infestations.

The following article is an introduction to the types of climbing plants commonly grown on exterior walls of a property, general and specific benefits and drawbacks, and some of the the most common climbers grown on UK properties. 

Types of Climbing Plant

There are three main types of climbing plant: self-clinging, twining, and rambling/climbing roses.

• A self-clinging plant does what it says on the tin: the plant produces tiny aerial roots or adhesive pads which stick to a wall or fence.
• Twining climbers produce tendrils which wrap around a support (trellis, cane or pergola, for example) in order to climb.
• Rambling or climbing roses need to be tied in and trained to cover a wall, as the plants themselves produce no suction or twining tendrils.

Considerations

Before buying your climber and planting it- consider whether it is suitable for your garden and wall: Ask yourself:

• What is the eventual height and spread of the plant likely to be? Does this fit in with the height and width of the wall?
• Will the plant need a support?
• What is the soil type? What direction does the wall face? Do these conditions suit the plant?
• Will I need to plant it in a container, or can it go straight into the soil?

The best source of information for specific varieties of plants is the Royal Horticultural Society’s (RHS) website. This offers information on all of the above, and advice on planting, care and common issues associated with each plant.

General Benefits

Perhaps the most obvious benefit to growing a climber on an exterior wall is aesthetic. From pretty foliage to colourful blooms, an otherwise dull wall or façade can be made into a feature when a climbing plant is grown over it. Aspects of a property that you might want to draw attention away from might be softened (or masked entirely) by a leafy climber.

There are also tangible environmental benefits to climbers, too. Climbing plants will boost biodiversity. The leaves and stems will provide vital nesting sites and shelter for a whole host of insects and birds. Plants producing flowers can encourage pollinators to your garden, whilst those producing berries can offer a much-needed food source for birds.

General Drawbacks

A common problem associated with many creepers and climbers is that of access.  Having a climbing plant growing from the ground floor can provide an ideal access route for pests, such as mice and rats, to enter a home via the roof space or windows. Intruders can potentially use strong climbers such as ivy to help gain access to a property.

A climbing plant covering an exterior wall or a good proportion of it can also hide a multitude of defects in a property. This can make it difficult to access or view problem areas, in turn making it that bit more difficult to identify a problem early on (for example, cracks) and then establish what is going on.

Common Climbers

Ivy

Ivy is perhaps the most commonly seen climber to adorn homes. The most popular species are Common Ivy (Hedera helix, also known as English Ivy) and Boston Ivy (Parthenocissus tricuspidata). Common Ivy is evergreen, whilst Boston Ivy is deciduous.

Ivy is a self-clinging climber, and as such will happily attach itself to any wall, fence or roof without support. Growth is rapid, and results in a dense layer of foliage in the form of three- or five-pointed leaves. Most varieties are hardy, can tolerate a variety of exposures and soil types.

Drawbacks of Ivy

Ivy undoubtedly has a bad reputation. Common Ivy produces very strong aerial roots; where brickwork is sound, these aerial roots should not cause a problem, however they can penetrate any cracks, holes and joints in masonry. The RHS warns that this can cause structural damage to a property. The aerial roots produced by Boston Ivy and Virginia Creeper (see below) are significantly weaker and so these species are not associated with structural damage.

Depending on the aspect of the covered wall, Ivy (and other climbing plants giving dense coverage) have been known to encourage damp and mould by trapping moisture against mortar that is not easily dried out by wind or sun.

The other issue here is growth: ivy grows at a prolific rate and can quickly get out of hand. Even if a property is structurally sound with no weaknesses in the brickwork, if it is left to smother a building, ivy can block or pull down guttering, displace roof tiles and block chimneys.

Lastly, when removed from a wall, ivy leaves behind an unsightly residue. Once the foliage has been removed, the small aerial roots will remain attached to the wall; a good scrub down or even a pressure wash may be needed to remove these completely.

Benefits of Ivy

Ivy has specific benefits when allowed to climb up a wall or building. Firstly, a covering of ivy can have an insulating effect, helping to maintain the interior temperature of a house. Research by the RHS and the University of Reading showed that ivy helped keep houses cooler during hot summer months, and also reduced humidity.

Secondly, Ivy has been shown to improve the air quality in a house. Research by London Goldsmith university has also shown that Ivy helps trap airborne particulates, therefore having a cleansing effect on the air in and around a property; the authors go so far as to describe ivy as being ‘ideal for air purification’.

Virginia Creeper

A close cousin of Boston Ivy (see above), Virginia Creeper (Parthenocissus sp.) is another self-clinging climber. This deciduous plant is best known for the dramatic red and orange hues of its autumnal leaves.  Similar in all other respects to Boston Ivy, Virginia Creeper grows rapidly and will quickly smother whatever it climbs. Some gardeners suggest helping Virginia Creeper establish with the use of supports such as canes, but in many cases it does fine on its own.

It should be noted that Parthenocissus quinquefolia is classed as an invasive (non-native) plant species in the UK, under Schedule 9 of the Wildlife and Countryside Act (1981). This means that, whilst it is perfectly legal to buy this plant and allow it to cover your property wall(s) or outbuilding, homeowners must ensure it does not grow into the wild. Precautions could include controlling growth by regular cutting back and carefully disposing of clippings (Gardeners World suggest a bonfire or enclosed compost heap), or considering alternative plants within the Pathenocissus family that are not listed on Schedule 9 (RHS has a list of suggested plants here ).

Climbing Hydrangea

Another deciduous self-clinging climber is the climbing hydrangea (Hydrangea anomala). It doesn’t require special conditions or maintenance to thrive, so would be a good choice for a novice gardener. In fact, the RHS has awarded the climbing hydrangea the Award of Garden Merit (AGM)- demonstrating it is a reliable, low-maintenance addition to a garden.

Although the climbing hydrangea produces aerial roots to attach itself to a wall, RHS advises using wire or a small trellis to support a young climbing hydrangea, tying each stem to the support until the aerial roots grow and attach securely. Whilst it can take some time to establish, this climber should eventually grow rapidly.

Twining climbers

Twining climbers will require support, in the form of a trellis or wires, in order to grow up an exterior wall. Consider the eventual height and spread of the climber before deciding which support will be best.

In using a support, homeowners can remove a twining climber with relative ease (as the plant is not attached to the property, but the support).

Some of the most popular twining climbers seen on UK homes include:

• Wisteria,
• Clematis (some varieties are best suited to sun, others for shade),
• Honeysuckle

Wisteria and Clematis produce colourful blooms, whilst Honeysuckle will also give off a distinctive fragrance.

Passionflower (Passiflora sp.) produces exotic flowers and, in some varieties, fruit (not all are edible, though). These plants make a striking addition to a property once in bloom, but be sure to choose a hardy variety if you want to grow it up an exterior wall. It should thrive on a trellis running up a wall that gets plenty of sun and is well sheltered.

Grape vines can also produce fruit as well as abundant foliage. These vines are best grown on sturdy supports such as wires fixed to a wall. According to RHS, growth can get out of hand, and careful pruning of tendrils and training is required to maximise fruiting and minimise the amount of leaf growth. As with passionflower, sunny walls that are largely sheltered from the elements are best.

Climbing/rambling roses

Evocative of the archetypal country house, climbing or rambling roses produce beautiful and often fragrant blooms to decorate an exterior wall. It is important to consider the aspect of the wall or structure that a climbing rose will grow over. Whilst many varieties thrive on a sun-drenched wall, RHS has a comprehensive guide for varieties best suited to shadier spots such as north-facing walls.

As climbing roses do not produce aerial roots, adhesive pads or tendrils, they require fairly extensive support: the stems should be loosely tied to a support structure (trellis, wire, pergola etc.) with enough room left for the stem to expand slightly.  Gardeners World suggest not to prune climbing roses within the first three years, instead focusing on ‘training’ new stems (tying them to the support trellis or wire). In particular, it is important to train stems in such a way as to encourage flowering where you want it; new growth needs to be trained horizontally as well as vertically to ensure a good spread. The process of training might seem daunting to a novice gardener, but David Austin Roses has produced a comprehensive video.

Summary

Climbing plants can decorate a home, boost biodiversity and air quality. However, some are associate with structural problems and pests. It is important to consider the soil type, area of wall to cover and aspect of the wall when deciding which climbing plant to grow on your property, as well as any supports you many need to put in place for the particular plant. There are a wide range of options available and the RHS is a reliable resource for novice and experienced gardeners. With any climber, but particularly those varieties which grow rapidly and aggressively over a wall or support, it is important to control growth to minimise the risk of damage in the form of blocking guttering or chimneys

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