How to Light a Living Wall

Why Living Walls Need Good Lighting

The World Health Organisation predicted that stress-related illness would be among the largest contributors to disease globally. Research has shown that incorporating direct or indirect elements of nature into the built environment — known as biophilic design — can reduce stress, blood pressure and heart rates, while increasing productivity, creativity and self-reported wellbeing.

'Biophilic' designed workplaces are reported to reduce absenteeism and improve productivity by 8 to 10 per cent, with rates of wellbeing boosted by 13 per cent. In the education sector, biophilic environments have witnessed an increase in test results by between 20 and 25 per cent.

Is it any wonder that living walls have started to appear in offices, hospitals and public buildings? But plants need light to thrive — and getting the lighting right is critical to the wall's long-term health and visual impact.

How Much Light Does a Living Wall Need?

Plants will not survive without an appropriate amount of light. Poor illumination slows photosynthesis, causing plants to wilt, yellow and eventually die. For photosynthesis to occur effectively, we need light levels of at least 1,000 lux for plants to thrive, with levels of 2,500 lux often required for demanding species.

Where natural light from a skylight or nearby window can supplement artificial sources, the energy cost and environmental impact are reduced. But many interior living walls are in locations with limited natural light — lobbies, corridors, internal atriums — making artificial lighting essential.

The type of luminaire is down to preference, but a proven solution is track-mounted spotlights that focus lumens onto the living wall surface. Track systems allow designers to play with beam angles for good coverage and enable quick reconfiguration as the planting scheme evolves.

What Colour Temperature for Plants?

Plants have evolved in nature to optimise photosynthesis at the ends of the visible colour spectrum:

• Blues (5000-6500K) encourage strong leaf and stem growth — essential for foliage-dominant living walls • Reds and oranges (2700-3000K) promote flowering — important for walls featuring flowering species

Natural sunlight provides a full spectrum of colour, so the ideal approach is to treat your living wall to a combination of blue and red wavelengths. In practice, this means using luminaires with good spectral distribution or a mix of colour temperatures.

For purely aesthetic accent lighting viewed by building occupants, a warm 3000K creates an inviting, natural feel. For plant health in low-light locations, supplementing with cooler 5000-6500K sources (or dedicated horticultural LED) ensures the plants receive the wavelengths they need to photosynthesise effectively.

How Long Should You Light a Living Wall?

For most indoor situations, plants should receive approximately ten hours of supplementary light per day, followed by a night of rest. This mimics the natural photoperiod that plants have evolved to expect.

Automated lighting controls — either simple timeclock switching or integrated DALI/Plexus scheduling — ensure the living wall receives consistent daily illumination without relying on manual switching. This is particularly important in environments where the building's occupancy hours don't align with the plants' lighting needs.

For living walls in 24/7 environments like hotels or hospitals, separate circuits or dimming schedules can maintain plant-appropriate light levels overnight without disturbing the ambient lighting scheme for building users.

Recommended Luminaire Types

• Track-mounted spots — adjustable beam angles, easy repositioning as planting changes. Available with high CRI for accurate colour rendering of foliage • Recessed adjustable downlights — for ceiling-integrated installations where a clean architectural line is required • Linear LED profiles — for narrow living walls where even wash lighting from above or below is more appropriate than spot illumination • Bespoke horticultural solutions — custom spectra LED systems for demanding or large-scale installations where plant growth is the primary objective

EOS offers track spots, adjustable downlights and bespoke LED solutions suitable for living wall applications. Our team can provide lighting calculations to ensure the correct lux levels reach the plant surface, accounting for throw distance, beam spread and the specific species in the planting scheme.