Walk into a garden centre and you will see boxes shouting about watts. Watts tell you how much electricity a lantern draws, not how much light it throws. Since LEDs replaced halogen, that gap has become enormous: a modest 5W LED can comfortably outshine an old 40W bulb, so the wattage printed on the packaging tells you almost nothing about what you will see from the kitchen window. Lumens are the honest number. Get them right and your patio feels warm and generous, your steps read clearly underfoot, and your borders gain depth after dark. Get them wrong and you have either built a runway or installed a row of dim little smudges.
Start with lumens, not watts
Lumens measure the total light a fitting produces. A decorative lantern bought purely for its looks might sit somewhere between 20 and 80 lumens, while a dedicated spot or flood can run into the hundreds or thousands. Both have their place, but they are not interchangeable.
Two things shape what you actually perceive: distance and beam angle. Thirty lumens at knee height along a path is plenty. The same thirty lumens mounted on a wall three metres from a dining table will vanish. A narrow beam concentrates light into a tight pool; a wide beam spreads it thin. If a listing gives lumens but no beam angle, treat the figure with caution.
How many lumens for each part of the garden
Treat these as starting points rather than rules, then adjust to your own eyes and surfaces. Pale stone and gravel bounce light around; dark decking and bark swallow it whole.
Patios and seating areas
For general ambience, aim for roughly 200–400 lumens per fitting, spread across two or more lanterns rather than one bright source. If you eat outside, a light above the table at around 300–500 lumens is enough to read a menu without glaring into anyone's eyes. Dimming matters more here than raw output.
Paths and driveways
Between 10 and 50 lumens per fitting, spaced every 1.5 to 2.5 metres, usually works well. The aim is a gentle rhythm that marks the edge of the route, not a lit runway. Bollards, low posts and stake lights all suit this job — keep them below eye level and angled down or across so you are not looking straight into the source.
Steps and level changes
Steps need the most care and the least light. Around 20–50 lumens washing across each tread shows the edge clearly. Fit lights to the side, or recess them into a riser, so the beam skims the surface instead of shining upward. A step you cannot see is a step you will trip on, so prioritise even coverage over brightness.
Borders, shrubs and trees
Uplighting a small shrub often needs only 100–200 lumens. A mature tree may want 300 lumens or more, but a single spot at the base rarely flatters it — two fittings at different angles give shape and avoid a flat, theatrical look. Aim the beam so it fades before the canopy ends. Light spilling into a neighbour's window or straight up at the night sky is simply wasted.
- Patio ambience: 200–400 lumens per fitting
- Dining table overhead: 300–500 lumens
- Paths: 10–50 lumens, spaced 1.5–2.5m
- Steps: 20–50 lumens per tread
- Shrubs and small trees: 100–300 lumens
- Large trees: 300+ lumens, ideally from two angles
Warm white or cool white? Colour temperature matters too
Colour temperature, measured in kelvin, changes how a garden feels. For almost every domestic setting, choose 2700K or 3000K. This is the warm, faintly amber light of a candle, and it flatters brick, timber, sandstone and foliage while sitting comfortably alongside light spilling from a kitchen window.
Cooler light — 4000K and above — reads as clinical outdoors. It flattens green leaves into grey, makes pale paving look harsh, and tends to draw more insects to the fitting on summer evenings. For a commercial entrance or a security light, cool white has its uses. Around a patio it rarely does.
One practical warning: two warm-white fittings from different brands may not match. Buy the whole set at once, or check the kelvin figure carefully. A 2700K lantern next to a 4000K one looks like a mistake, because it is one.
IP ratings: what a UK garden actually demands
The IP rating tells you how well a fitting resists dust and water. Two digits: the first covers solids, the second covers water. Outdoors in Britain, rain arrives sideways, borders stay damp, and frost does its own damage.
- IP44 — splash-resistant. Fine under a porch roof, in a covered pergola or a sheltered courtyard. Do not bury it or leave it in open ground.
- IP55 — dust-protected and resistant to water jets. A reasonable minimum for wall lights in exposed positions.
- IP65 — dust-tight and jet-resistant. A sensible default for general garden lanterns, bollards and spots.
- IP67 / IP68 — able to withstand immersion. Use these for in-ground fittings, buried cable joints and connectors.
Remember that the rating applies to the fitting, not to your wiring. Cable joints, transformers and plug connections need their own protection — commonly IP68 gel-filled connectors, or a sealed enclosure above ground where you can inspect it. Keep 230V plugs indoors or inside a proper weatherproof box, and never leave a connection sitting in a puddle at the bottom of a border.
If you are running a 12V system, check the transformer has enough capacity for every fitting on it, and keep cable runs reasonably short. Low voltage drops off over distance, so the last lantern on a long run can end up visibly dimmer than the first.
Layering beats brute force
The most pleasant gardens use three levels of light: soft markers at ground level, mid-height lights around seating, and one or two accents in planting or on a wall. Each layer can be modest because your eyes adapt. A single 800-lumen flood on the back wall will just make everything else look dark.
Add control and the whole scheme becomes more usable. A timer or smart switch means lights come on as you get home. A PIR sensor on a side path gives you light when you need it and darkness when you do not. Dimmable fittings let you soften the patio after dinner. And one rule is worth keeping: if you can see the bulb or the LED itself, the light is in the wrong place. Shield it, angle it down, or move it.
Before you buy: a five-minute checklist
- Measure the space and note what each area is for — seeing, sitting, or showing off a particular plant.
- Add up the lumens you think you need, then halve it. Most gardens are over-lit.
- Check the kelvin figure. 2700K or 3000K for almost everything at home.
- Match the IP rating to the position, not to the look of the fitting.
- Decide how the lights will be switched, timed or dimmed before you commit to a set.
Buy one fitting first and test it in position after dark. Live with it for an evening, see how it lands on your paving and your plants, then order the rest. That single step saves more disappointment than any lumen chart.
Photo: bodiantal / Pixabay
