Landscape lighting isn't a complicated system, but it's an unforgiving one. Pick the wrong fixture, the wrong wire, or the wrong transformer on day one, and you'll live with that choice for the next decade. The good news: nearly every common install mistake is a buying decision, not a labor one. Avoid these ten pitfalls in your cart and you've already beaten 90% of DIY installs.
THE QUICK ANSWER
The biggest landscape lighting mistakes happen at checkout — not on the ladder.
Oversize your transformer by at least 20%, space path lights 6–8 ft apart, choose brass over aluminum for a permanent install, and never run long wire runs on 18-gauge cable. Get those four right and the rest is details.
1. Ordering a transformer with no headroom
The single most common mistake is buying a transformer that exactly matches your total wattage — then adding two more fixtures later and watching half the yard go dim. Low-voltage transformers should be sized at 120% of your total fixture wattage; the extra 20% is headroom for voltage drop and future additions. A multi-tap unit like the MLR-TF04 600W also lets you dial voltage per run, which solves dimming by itself. Start with our transformer sizing guide before you order anything else.
2. Spacing path lights wrong
Too far apart and you get dark gaps; too close and the walkway looks like a runway. The rule of thumb is 6–8 feet between path lights, staggered on both sides. Curves and steps need tighter spacing (4–5 ft); straight, wide driveways can stretch to 10 ft. Don't eyeball it — walk the path with a tape measure first. Our full guide on path light spacing has a fixture-count formula.
3. Choosing aluminum to save $20 a fixture
Powder-coated aluminum costs less on day one, but the coating is the fixture's weak point — it fails in 10–15 years, and in coastal climates in 3–7. Solid brass forms a self-protecting patina and lasts 50+ years. For a home you plan to keep, brass is dramatically cheaper per year. Read the full brass vs aluminum comparison before you default to the cheaper option.
4. Ignoring voltage drop on long runs
Low-voltage wire loses voltage over distance. Run 200 feet of 18-gauge cable to your far fixture and it might be getting 10V instead of 12V — noticeably dimmer. The fix is twofold: use a heavier gauge (12/2 for runs over 50 ft), and split long runs back to the transformer rather than daisy-chaining everything in one loop. A multi-tap transformer lets you bump those long runs up to 15V to compensate.
5. Buying the cheapest wire in the box
18/2 wire sounds fine until you bury it. Thin jackets crack in winter, and thin gauge amplifies voltage drop. For a permanent install, spec 12/2 low-voltage direct-bury cable for main runs, and 16/2 for short drops to fixtures. It costs a bit more per foot — and saves you redoing the whole trench in three years.
6. Picking the wrong beam angle
A spot (15–30°) on a wide wall looks like a flashlight; a flood (60–120°) on a small tree looks like a porch light. Use narrow spots (15–25°) to wash specimen trees and architectural columns, medium floods (36–60°) for shrubs and fences, and wide floods (up to 120°) for wall grazing. When in doubt, buy the narrower optic — you can always back a light off the subject to widen the pool.
7. Mounting tree lights too high
A spotlight shoved up into the canopy at eye level lights nothing but branches. The right height is usually 2–4 feet off the ground, aimed up at the trunk, so the light rakes the bark and branches rather than blasting the leaves. For large canopy trees, you may need two lights at opposite sides of the trunk to feather the canopy evenly.
8. Forgetting the daytime look
What does the install look like at 2 PM? Black wire across fresh mulch, plastic fixtures catching the sun, and cheap stakes sticking out of the lawn tell visitors exactly where your "DIY" project ends. Choose fixtures with a finish that ages well (brass, again), and plan the wire route before you lay lights. Our guide on hiding landscape wire covers the five professional methods.
9. Buying sealed fixtures you can't service
"Lifetime LED" fixtures look great until the driver fails in year four and the whole unit hits the trash. Buy fixtures where you can replace the bulb, the lens, or at least the driver. A brass spotlight that takes a standard MR16 bulb will outlast the sealed plastic housing next to it by a decade.
10. Ordering one fixture at a time
Lighting is a system. Order two path lights, decide you like them, then come back for more six weeks later — and the new batch ships in a different finish, a different beam angle, or (worse) a different brand. Sketch the whole yard first: count fixtures per zone, choose one fixture family, and order everything in one cart. Consistency of light temperature (stick to 2700K) is what makes the whole install look designed rather than accumulated.
Build the system right the first time
MALORY's brass path lights, spotlights, and in-ground well lights are designed as one coordinated system — same 2700K warm glow, same solid brass build, matched with a multi-tap transformer. Order the whole layout at once and it'll look finished on day one.
Shop Path Lights Shop Spotlights Shop Well LightsFrequently Asked Questions
How many landscape lights do I need for a typical yard?
Average home uses 8–15 fixtures: roughly one path light every 6–8 feet along walkways, 2–4 spotlights on specimen trees, and 1–2 well lights in planting beds. Count your fixtures first, then size the transformer to 120% of total wattage.
Should I choose warm white or cool white landscape lighting?
Stick to 2700K warm white for residential yards. 3000K is acceptable on modern homes, but anything cooler reads commercial and harsh. Mixing color temperatures across your yard is the most obvious "DIY tell."
Can I add more lights later?
Yes — if you sized the transformer with 20% headroom and ran heavier-gauge main wiring. That's exactly why oversizing the transformer on day one matters: it's the cheapest insurance against future expansion.
How deep should I bury low-voltage wire?
3–4 inches in mulch beds is fine; run it through PVC conduit where it crosses walkways or patios. Low-voltage wire does not need frost-depth burial — that's a 120V requirement.
Is brass really worth the extra cost?
If you own your home for 10+ years, yes. Brass fixtures last 50+ years and develop a protective patina; powder-coated aluminum fails in 10–15 years. The per-year cost of brass is lower despite the higher upfront price.
Bottom line: The difference between a yard that looks professionally lit and one that looks DIY is decided at checkout — transformer size, spacing, material, and wire gauge. Get those four right, hide the wire, and the install will quietly look great for decades.
