How do you choose an LED grow light that keeps houseplants alive all winter?

Wired’s tested guide to LED grow lights boils the choice down: full-spectrum (sunlight-like) light, hung closer than you think, run 12–16 hours a day on a timer, sized to the plant or shelf you actually have. Distance and hours matter more than the wattage printed big on the box.

By November, your basil leans toward a grey window like it is homesick, and the fern has given up. Short answer: Most houseplants do not need a greenhouse — they need the right light, at the right distance, for enough hours a day. Wired’s tested buying guide to LED grow lights, published October 17, boils the choice down to this: buy full-spectrum light, hang it closer than you think, run it on a timer for roughly 12 to 16 hours a day, and size it to the shelf or single plant you are saving.

“Full-spectrum” in plain English means the light imitates sunlight’s whole rainbow instead of the purple-pink glow of older grow lamps — plants use more of it, and your living room does not look like a nightclub. Distance and daily hours matter more than wattage, because light weakens fast with distance: a modest light six inches above the leaves beats a powerful one across the room. Modern LEDs run cool, so heat is mostly about the fixture’s power supply and a little airflow — not cooking your plants.1.

Match the light to the footprint. One struggling plant needs a small bulb or panel; a whole shelf needs a bar or panel that covers its full length evenly.2. Choose full-spectrum, white-looking light.

It feeds plants at every growth stage and keeps the room looking like a room.3. Hang it close. Start 6–12 inches above the leaves for most compact LEDs, then adjust: stretching, pale, leggy plants want it closer; bleached leaves mean back off.4.

Put it on a timer. Twelve to sixteen hours a day, same schedule daily. A simple outlet timer is the cheapest upgrade in the setup — order one with the light and winter runs itself.5.

Mind heat and air. LEDs are cool next to old lamps, but check the fixture is not warming a shelf above it, and let air move.6. Rotate the plants weekly.

A quarter-turn stops the permanent lean toward the light and keeps growth even.Pro tip: The common mistake is buying by wattage marketing. Judge a light by the area it covers at the distance you will hang it — coverage, not watts, decides whether plants thrive.Ad’s take: Winter does not have to be a plant funeral. One decent light, hung close, on a timer, and your windowsill garden survives February.