Grow Lights for Succulents: Which Kind, How Close, How Long

Signs you need one

Indoors, succulents need a lot of bright light. When they aren't getting enough, they tell you.

Stretching

Tall, spindly new growth that's pale in color. The plant is reaching for light it can't find. More on leggy succulents.

Flattening rosettes

Rosette succulents open up and flatten their leaves to catch more light.

A droopy jade

A jade plant in poor light grows deep green leaves on drooping stems.

No bright window

If no window gives a bright enough spot, don't wait for symptoms. Start with a light.

Which kind of light?

LED, the easy choice

Efficient, long-lasting and cooler running than fluorescent tubes. Pick one labeled full-spectrum (sometimes sold as "daylight"). Most LEDs can sit 12 to 24 inches from the leaves.

Fluorescent, still fine

High-output T5 tubes are the efficient choice. They need to be closer, 6 to 12 inches from the leaves, and fade with age, so replace the tubes every one to two years.

Incandescent, skip it

Ordinary bulbs run hot, waste energy, burn out quickly and give mostly red light with little blue. They're not good plant lights.

Spectrum and brightness, in plain words

Spectrum is the mix of colors in the light. Plants mainly use red and blue. Many LED grow lights give out mostly those two, which is why they glow pink or purple, and why everything under them looks pink too. Some LEDs cover only a narrow range of colors, which means less useful light for the plant, so Iowa State Extension recommends full-spectrum fixtures. They look white, and you can see your plant's real colors, which helps when you're checking it for stretching or scorch.

Brightness on the box is easy to misread. Lumens measure how bright light looks to your eyes, not how much a plant can use. Growers measure that as PPF or PPFD, if you see those on a label. At home, the control that matters most is distance. Move the light closer for more, farther away for less.

How to set one up

Put it close. Set succulents within about 12 inches of the light. If your light came with directions for distance, follow those.

Plug it into a timer. A timer switches the light on and off for you. 12 to 14 hours a day suits most plants, and succulents can take up to 16.

Leave them a night. Never run it more than 16 hours a day. Plants need a dark period too.

Watch and adjust. Stretching or pale growth means too little light, so move it closer. Bleached or scorched patches, or unusually red leaves, mean too much, so raise it a little.

Keep up as they grow. Raise the light as plants get taller, so the gap stays about the same.

FAQ

Do succulents need a grow light?

Not if they're thriving in a bright window. If they're stretching, turning pale, or you have no bright window at all, a grow light is the fix.

What's the best grow light for a jade plant?

The same as for other succulents. Jade does best with four or more hours of direct sun a day, so in a dim room a full-spectrum LED close to the plant, on a timer, saves it from the floppy, dark green growth of a jade in poor light.

Do I need a special grow light, or will a shop light work?

A plain plug-in LED shop light labeled full-spectrum or "daylight" works too. Iowa State Extension suggests one as an alternative to a dedicated grow light.

Can I leave a grow light on 24 hours a day?

No. Plants need a dark period, so keep it to 16 hours a day at most. A timer makes this automatic.

Are purple grow lights better than white ones?

Not necessarily. Purple lights are heavy on the red and blue that plants use most. Iowa State Extension recommends full-spectrum fixtures, which look white and let you see your plant's real colors.

Grow lights for succulents