Do Expensive Grow Lights Matter?


Shop lights
Okay, it's one thing if you are growing a cash crop like marijuana in the guest room and need super high-intensity light to bring the crop in before the cops arrive. Or if you live in Alaska and morale depends on growing peppers in the house.

But what if you just want to start a few seedlings?

I'm don't enjoy starting seeds for the same reason I don't enjoy houseplants.  To me, the entire interest in gardening revolves around the mysterious interaction between plant and soil and the million distinct species of bacteria in a gram of it.

Still, I start seeds in the house just to have the varieties I want and things like lemongrass that the nurseries around me don't carry.  I use $10 shop fixtures from Lowe's with two $3 40-watt cool spectrum 48-inch T-12 fluorescent tubes plugged into each one.  They are hung from chains that I raise and lower on an S-hook, and they are plugged into a cheap timer.  For the ten weeks that the peppers and eggplants take, works fine.

When I was about to do my single TV appearance thus far for my book, which argues that everybody with a bit of soil ought of grow a little food, the producers were worried that I was leaving Manhattan out of the equation.  I said, "Oh community gardens are fantastic!  You can grow an amazing amount of food in a small space!"

"But what if you don't have a community garden plot?"

"Well, there are really nice containers for balconies and terraces!"

"What if you don't have a balcony or terrace?"

"Well, if you have the right south-facing window, you'll be able to grow lettuce and herbs."

"What if you don't have the right window?"

Sheesh! So I decided to press a little further into the question of what could be grown in an apartment without a ridiculous investment or completely uglifying the joint.

I called a gardening catalog business, which offered an array of grow light fixtures for between $100 and $350.  The $130-dollar one was labeled "amazing" and had a photo of a fruiting pepper underneath it.  I asked, "Can you really grow peppers or tomatoes under this?"

The answer was, "Not really."  As in, without wind or bees, you have to hand-pollinate the plants and you tend not to get much fruit for the space anyway.

So I decided to be simple and just grow some salad in my basement for the TV demonstration.  To show what was available in the marketplace, I ordered a slightly downscale grow light that was still considerably more expensive than my set-up, but also looked more attractive in photos.  It was back-ordered and wouldn't arrive in time.  Instead, I started my arugula under my cheap shop lights.

Grew fast, looked great,…and in the organic potting soil I used, even tasted just right, spicy! 

Yes, my T-12 set-up is not as efficient as T-8 or T-5 bulbs.  But the Big Box stores carry those, too.

Unfortunately, they carry them in a confusing array of unattractive choices that may leave the gardener wandering around in a daze. (Just to cut through the confusion, cool spectrum light is reportedly best for leaf growth and therefore lettuce and seedlings. Wikipedia tells me cool spectrum is a color temperature of 5000K or more.  That number is marked on the boxes.)

I think grow-light sellers are profiting from this confusion. But are their products really superior?  I put it to the crowd: Unless you are trying to get fruit indoors without a window, is there any reason not to just buy what the Big Box stores have got?


  1. No, absolutely not. At the university where I study/work, lots and lots of researchers grow plants in special “growth chambers” — sealed boxes which allow them to minutely control and record temperature and humidity for careful experiments. And what sorts of lights to they use in them? Plain old shop lights and florescent bulbs. And yes, they grow plants to flower and fruiting in them. Greenhouse growers use much more expensive high intensity discharge lamps — but their only advantage is that they produce a lot of light from a small fixture, so they don’t block the sun during the day. Growing indoors, just get a couple shop lights, and surround them with something painted white or covered with aluminum foil to reflect the light back on the plants. For just a few seedlings, you can even use those spiral compact florescent bulbs in a couple cheap desk lamps positioned right over your seedlings.

  2. I have to say I bought 2 sets of grow lights at around the 150ish range this year, as I’ve increased my veg. garden about 300%, and there is not enough room on the windowsills anymore. They came from a very well known and respected catalog.

    I’m ridiculously unhappy with them for 2 reasons. One, when you adjust the lights up and down, the bulbs tend to go out. When I called the company they suggested I jiggle the wire until they go back on. Pardon me, but at $150 a piece I don’t think that should happen – now maybe if I had paid $20 I wouldn’t mind! Two – instead of the flats commonly used (and what I’ve always used) They come with cow pots, that sit on a wicking mat in a tray. Sure it makes the watering easier, but I”m concerned that the seedlings are staying too wet – I’m just waiting for the tomatoes to get damping off.

    Thinking I need to put some backups in jiffy trays in the window this morning!

  3. I have been growing seedlings under shop lights in my basement and garage for 20 years and am doing quite fine with them, thank you. I did research many years ago on grow lights vs. the 1 warm/1 cool flourescent bulb setup I was using and found a Cornell study supporting my theory that the traditional “grow” light promoted premature flowering, which is not a good thing for transplants. African violets, yes. Veggie seedlings, not so much. I also use a fan in my setup so as not to end up with too-tender plants so I can harden them off quicker. The resulting transplants are every bit as beautiful as greenhouse stock and I know exactly what conditions the were grown under.

  4. MisChelle — thank you for the fan idea. We spend a great deal of time petting our larger seedlings to toughen them but a fan sounds much more effective.

  5. i have a $100 t5 system. i went to the store that specializes in growing pot, and told them i was going to do “regular plants”, and that i was going to grow them in my dining room.

    they pointed me to a hydrofarm 4×2′ fixture. its a great size, big enough for a standard seed flat, with a few plants on the outside. its good looking(ish).

    things seem to be growing…. about the same as before! but its a nicer fixture. easier to the plants in a good spot

  6. I wanted to avoid being overwhelmed in Home Dept, where the service often frankly sucks, and instead ordered this attractive light and stand from Johnny’s. I thought with their reputation it would be great. Well, I like the stand but the light only has one bulb–leaving a narrow space for growing seedlings.
    I prefer growing in the ground too, but I wanted to advance to starting my own peppers and eggplants and thought it would help with succession planting. It’s kind of a hassle.

  7. I have never bought any kind of grow lights. I start my seedlings in the windowsill, or under plain old lamps that have those spiral energy-saver bulbs in them. They do just fine- in fact this year my tomato and pepper seedlings grew faster than ever! As soon as they’re big enough I stick them outside under glass or plastic so they can get sunlight- even when there’s still snow on the ground or it’s a cloudy day they do better there.

  8. I have a couple of expensive grow lights, and they *defintely* put out a lot more light. Is it enough to justify the expense? Probably not. It’s definitely easier to grow seedlings though as you don’t need to keep the bulbs an inch above the plants.

    I use them to also overwinter cuttings from tender plants so I don’t have to buy again each spring.

    They use almost triple the energy (210W vs 80W) but are they 3x brighter? I don’t have a light meter, but probably.

    Do I need to have them? Nope. Am I glad I have them? Yes!

  9. I’ve also used shop lights for many years. They sit on an array of phone books and other things that I use to control the height. I also use a heat mat to speed up the germination process. They are set up in a dormer space just outside my bedroom; during the season, they are the first thing I see in the morning and the last before I go to bed!

    I’m experimenting this year by keeping the 6-packs covered with the top of a disposable clear plastic food container top. (I don’t start many things from seed, so it fits 2 six-packs perfectly.)I have found the potting medium dries out too quickly otherwise.

    I got a bit of a late start this year, so am impatiently waiting for things to germinate.

  10. I’ve been using shop lights for years. I overwinter many annuals and start my seeds. Several years ago Fine Gardening had a seed starting stand that my husband built that I use 4 shop lights. I’ve never had any problems with these inexpensive lights.

  11. My seedlings tended to to be a bit spindly and weak when my seed starting set-up involved just one shop light (with 2 florescent tubes) over a regular sized nursery tray (wide enough for 2 six-packs). During that time we tried a variety of florescent light bulbs, both standard cheap ones and expensive grow lights and didn’t see much difference in plant health, though I believe it’s best to use both red and blue spectrum lights, not just one color.

    A few years ago we switched to a new system using a wider, rubberized tray (3-4 six-packs wide) under two shop light fixtures with a total of 4 fluorescents over each tray. Now we’re getting beautiful, vigorous seedlings. From this experience, I’m led to believe that the amount of light makes more of a difference than the type of light.

  12. I am so glad that this is being discussed. I have only been growing from seed plants that can be seeded directly outdoors. If it has to be started indoors I have to buy started transplants which greatly inhibits my options. This past year I started to look into grow lights and did not want to pay for these expensive options. I knew you could build your own with shop lights but didn’t know where to start. I will definitely be using this information and starting everything from seed next year, at this point it is too late for this year. Thanks everyone for all the comments! I do wonder if people who use shop lights notice any significant difference in their energy bills when they are running the lights for seedlings?

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