Living Walls: Build a Green Wall That Lasts

A living wall can turn a bare fence, shed or house front into a sheet of green, but it lives or dies by its watering. Get the water, the fixings and the plant choice right, and it will look good for years. Get them wrong, and it browns off in a single summer.

This guide is for anyone ready to build one. It covers which system to choose, how to fix it safely, how to set up drip watering, and which plants last on a UK wall. Just after ideas for using your walls and fences? The guide to vertical gardening ideas for small spaces compares trellis, pocket planters and gutter gardens too.

What is a living wall, and why do so many fail?

A living wall is a frame of pockets, trays or troughs fixed to a wall, with plants rooted in compost on the wall itself. That makes it different from a wall of climbers, which root in the ground and creep up over a few years. A living wall looks full from day one. The catch is that its plants have only a small pocket of compost to draw water from.

Most dead living walls come down to three problems:

• Uneven watering. The top row dries out while the bottom row stays soggy.
• Weak fixings. Wet compost is heavy, and fixings in render or a fence panel pull out.
• The wrong plants. Shrubs and fast spreaders swamp the pockets within a season.

If you’d rather have something cheaper and lower-maintenance, evergreen climbers for year-round cover will green a wall more slowly with almost no watering once established.

Which living wall system should you choose?

There are three main types for home gardens. Felt pockets are the cheapest and easiest for a first wall. Modular trays give the most even growth. Stacked troughs are the most forgiving for beginners.

For a first wall on a shed or house, felt pockets are good value. For a display you want to keep for many years, trays are worth the extra cost and weight.

Trays clip onto rails and hold a decent amount of compost. That helps the roots stay evenly moist between waterings.

How to build a living wall step by step

A small DIY wall is a weekend job if you’re handy with a drill. Work in this order.

1. Check the wall can take the weight. Wet compost and plants are heavy, so fixings must go into solid brick or block. Never rely on render, plasterboard or a fence panel. If in doubt, ask a builder.
2. Fit a waterproof membrane. Fix a pond liner or root-barrier sheet to the wall. This keeps damp off the brickwork.
3. Add battens for airflow. Screw treated timber battens over the membrane. The gap behind lets air dry the wall.
4. Mount the system. Fix the felt panels or tray rails to the battens, level and straight. Run the drip pipe along the top.
5. Plant from the bottom up. That way you don’t knock out plants you’ve already put in.
6. Run the water and check every dripper. Blocked drippers are the most common early fault.

Membrane first, then battens. This layer protects the wall behind and gives the frame something solid to hang on.

Planting the pockets

Knock each plug out of its pot and loosen the roots. Firm it into peat-free compost so the crown sits level with the pocket lip. Pack plants closely for quick cover, and work along each row before moving up. Buy a few extra plugs of your main plants to fill gaps after the first winter.

Firm each plug in with the crown level with the pocket lip. Close planting means the wall knits together in one season.

Watering a living wall: the make-or-break job

Use drip irrigation on a timer. Plants in pockets have no soil to fall back on, so water has to arrive little and often, top to bottom. Hand watering can’t keep up: the top row dries out within hours while gravity soaks the bottom.

A simple home setup looks like this:

• A water tank at the base, which a water butt can top up.
• A small submersible pump lifting water to a pipe along the top.
• Drip lines with a dripper at every pocket or tray.
• A timer running short cycles.

Run several short cycles a day in summer, and cut back to one in winter. Give the top row an extra dripper, because it dries fastest. On a tall wall, split the watering into two zones so the top gets its own supply.

A liquid feed at half strength through the tank every couple of weeks in spring and summer keeps plants growing. Flush the system with plain water now and then to stop salts building up. A tank topped up from a water butt cuts mains use, and the guide to rainwater harvesting shows how to collect more.

One dripper per pocket, fed from a pipe along the top. Even watering from here keeps the whole wall alive.

The best plants for a living wall in the UK

Choose plants with shallow, fibrous roots that cope with a small pocket of compost. Then let the direction your wall faces decide the rest.

For a shady north or east-facing wall, build a backbone of evergreens:

• Hardy ferns such as Dryopteris affinis, Polystichum setiferum and hart’s tongue fern (Asplenium scolopendrium).
• Heuchera for leaf colour all year, in wine, lime and amber shades. The heuchera growing guide covers varieties.
• Bergenia and tiarella for solid leaves and spring flowers.
• Ajuga, Vinca minor and lamium to trail over the pocket edges.

For a sunny south or west-facing wall, pick plants that cope with heat and dry spells:

• Thyme, sedum and sempervivum.
• Erigeron karvinskianus, the Mexican fleabane, for months of little daisies.
• Small grasses such as Carex oshimensis ‘Evergold’ and Festuca glauca.
• Compact herbs such as chives and marjoram for an edible wall.

A north or east wall is the easier place to start, as it dries out more slowly. For more ferns that suit damp shade, see hardy UK ferns.

Ferns, heuchera and bergenia on a shady wall. An evergreen backbone like this keeps the wall green through winter.

Planting a living wall for bees

A sunny wall planted with erigeron, thyme, marjoram and sedum draws bees from late spring into autumn. The dense leaves also shelter spiders and beetles, which small birds come to hunt. It’s a handy way to add flowers where there’s no room for a border, such as on a balcony.

A sunny balcony wall packed with erigeron and thyme. Small flowers like these keep bees busy for months.

Month-by-month living wall care

Ferns and heuchera shrug off a frosty morning. Hardy evergreens are what carry a living wall through a UK winter.

Common living wall mistakes

• One drip line for a tall wall. The top dries out while the bottom drowns. Split tall walls into two watering zones.
• Fixing to render or a fence. It can’t hold a wet wall. Fixings must reach solid masonry.
• Skipping the membrane. Damp gets trapped against the brickwork. It’s a cheap layer that protects the house.
• Planting shrubs or thugs. Vigorous plants outgrow the pockets in a season and shade out everything else.
• Relying on a watering can. It works for a week or two, then the top row dies. Plan the pump and timer from the start.
• Ignoring vine weevil. The grubs love heuchera roots in compost. If a plant wilts and lifts out easily, check the vine weevil guide.

Ready to sort the watering? Read our guide to choosing a drip irrigation kit next, or browse more garden design guides for the rest of your space.

Frequently asked questions

Do living walls damage the wall behind them?

Not if you fit a waterproof membrane and a ventilation gap. The membrane keeps moisture off the brick. Treated battens hold the frame a few centimetres off the wall so air can dry it. Fixed straight onto bare render with no membrane, constant damp will spoil the surface over time.

What plants are best for a living wall in the UK?

Evergreen ferns, heuchera, bergenia and tiarella are best for shady walls. For sun, use thyme, sedum, erigeron and small grasses such as Carex. Pick plants with shallow, fibrous roots that cope with a small pocket of compost. Avoid shrubs and fast spreaders, which soon outgrow the pockets.

How do you water a living wall?

Use drip irrigation on a timer, with a dripper feeding every pocket or tray. Run short cycles several times a day in summer and cut right back in winter. Hand watering rarely works for long, because the top row dries out first while the bottom stays wet.

Can a living wall survive a UK winter?

Yes, if the plants are hardy and the pipes can’t freeze. Choose fully hardy evergreens, lag the pump and pipework, and drain exposed lines in a hard frost. The bigger winter risk is a frozen dripper leaving a patch of plants dry, rather than the cold itself.

How heavy is a living wall?

Heavier than most people expect, because wet compost weighs a lot. A watered wall of a few square metres can weigh well over a hundred kilos. Fix the frame into solid masonry with proper heavy-duty fixings. If you are unsure your wall can take it, ask a builder first.

Is a living wall the same as a green wall of climbers?

No, a living wall has plants rooted in pockets on the wall itself. Climbers on a trellis root in the ground and slowly cover the wall over a few years. Climbers are cheaper and need far less watering. A living wall gives instant, dense cover but depends on its irrigation.