A lit garden is a lit habitat. Most of the harm is avoidable and most of the fixes make the lighting look better, not worse — which is the part people don't expect.
The four things that matter
- Point it down. Light above the horizontal does nothing for you and everything for skyglow. Shielded fittings, no upward tilt.
- Keep it warm. Blue-rich white light is the most disruptive part of the spectrum for wildlife, and the least flattering for planting.
- Use less of it. Almost every garden we are asked to fix is over-lit. Fewer, lower, dimmer fittings read as atmosphere; more, brighter ones read as a car park.
- Turn it off. Nothing in a garden needs lighting at 3am. A timer is the single most effective wildlife measure available and it costs about twenty pounds.
Bats, and the guidance that actually exists
All UK bat species and their roosts are legally protected, and lighting is one of the main ways a domestic garden affects them. The Institution of Lighting Professionals and the Bat Conservation Trust publish joint guidance — Guidance Note GN 08/23, "Bats and Artificial Lighting at Night" — and it is worth knowing what it asks for, because almost none of it is difficult in a garden.
| What the guidance asks for | What that means in a garden |
|---|---|
| Colour temperature 2700K or lower, with peak output above 550nm and no UV | Warm white or amber only. Our 2700K range meets it; the 2200K amber fittings are better still. Nothing in our range emits UV. |
| Upward light ratio negligible or zero, with no light output above 90° and no upward tilt | Shielded fittings, cowls and snoots. An uplighter aimed into a canopy should be tightly beamed and shielded so the spill stops at the tree. |
| Part-night lighting, dimming to no less than 10–20% or switching off entirely | A timer or astronomical clock. Off by 11pm gives you the whole evening and gives the garden the whole night. |
| Motion sensors on a 1–2 minute timer for residential lighting | Security lighting should be on a PIR and a short timer, not burning all night. |
| 0.2 lux horizontal / 0.4 lux vertical as effectively dark | Leave the boundaries, the hedge line and the far end of the garden genuinely unlit. That is where bats commute. |
The practical version: light the middle of the garden, not the edges of it. A hedge, treeline or watercourse left dark is a corridor; lit, it becomes a barrier.
The other residents
- Moths and insects. Attracted to short wavelengths and killed by exhaustion around bright fittings. Warm, dim, shielded and timed-off is the whole answer. Amber at 2200K is measurably less attractive to flying insects than 2700K white.
- Hedgehogs. Avoid lighting the base of hedges and boundary gaps, which are the routes they use between gardens.
- Birds. Lit trees affect roosting and can bring dawn song forward by hours. If you uplight a tree that is roosted in, put it on a timer that goes off early.
- Ponds. Amphibians and aquatic insects are strongly affected. Our underwater kits come in 2200K amber for exactly this reason, and a wildlife pond is a good place to choose amber over white even though white looks more dramatic in a photograph.
Your neighbours
Artificial light spilling onto someone else's property can amount to a statutory nuisance under the Environmental Protection Act 1990, and councils do act on it. Long before that, it is simply bad manners and it is almost always caused by one badly aimed floodlight.
The fix is the same as everything else on this page: shield it, aim it down, dim it, and put it on a timer. Then go and stand in next door's garden and look back at yours. It takes two minutes and it is the only test that counts.
What to buy
- Dark Sky Friendly — shielded, downward-facing and zero-glare fittings.
- Wildlife Friendly Lighting — warm and amber output, shielded optics, low spill.
- Timers, photocells and astronomical clocks — the cheapest thing on this page and the most effective.
If you are near a known roost, a river or an SSSI, or your lighting forms part of a planning condition, take proper advice — this page is general guidance, not an ecological assessment.
Sources
The colour temperature, upward light, dimming, sensor timing and lux figures are from ILP Guidance Note GN 08/23, "Bats and Artificial Lighting at Night", published jointly with the Bat Conservation Trust. The rest — hedgehogs, birds, neighbours, and every opinion about over-lighting — is our own view.