Homemade grow lights — Start your own seeds and transplants

Special guest post by Matthew

You can spend a lot of money on a grow light setup and special light bulbs, but all you really need is a 48” shop light (or a couple), and a warm white and a cool white bulb.  I was a little skeptical at first, but this combination has worked fine for me for a wide variety of seedlings.   I’ve started most everything common and some decidedly uncommon things.*

My fixtures take either T8 or T12 fluorescent tubes — I use T8 for greater energy to light efficiency as compared to T12.  It is important to be careful how old your bulbs are, as long fluorescent tubes lose their efficiency long before they die.

I learned this the hard way — my seedlings were getting long and spindly instead of staying shorter and being robust.  I replaced the bulbs and had much better results with my next round of seedlings.**

You’ll also need a shelf at least as wide as your lights… wider is really not necessary, but a little extra can give you somewhere to put odds and ends, even if that space is no good for growing.

I strongly recommend installing your lights on chains so they can be moved up and down as needed for the height of your transplants…. And to allow you to use your heat box when it’s appropriate.  It’s also well worth taking the trouble to center the light fixture back to front.

I also recommend an extension cord long enough for your needs, an automatic timer to turn the lights on and off at about a 16 hour day (for most plants), and an electrical plug splitter (if you have more than one light fixture) so you can plug your lights into the timer.

Happy growing!

*I’ve started the following:

  • Broccoli
  • Cauliflower
  • Collards
  • Kale
  • Cabbage
  • Celery
  • Celeriac
  • Parsely
  • Onions
  • Leeks
  • Tomatoes
  • Tomatillos
  • Peppers
  • Eggplants
  • Hardy Kiwi
  • Squash
  • Melons
  • Fennel
  • Various flowers
  • Strawberries
  • Rhubarb
  • Asparagus
  • Hardy Kiwi
  • Kholrabi
  • Lettuce
  • Spinach

**Any store that sells fluorescent tubes and bulbs should accept spent tubes/bulbs for recycling. Please do not place in the trash — they contain mercury!


  1. EcoCatLady says:

    Wow! I am quite impressed! I fear I just stick mine in a south facing window with an old clear plastic bin over them to keep the cats out, and they’re on their own! They do get a bit leggy sometimes, but that’s never really been a problem. I’ve thought of getting a grow light or something, but in the end laziness usually prevails. But perhaps I’ll give your system a try.

    What does T8 & T12 mean?

    1. Melissa @ HerGreenLife says:

      The numbers (8 and 12) refer to the diameter of the bulb. T8 bulb diameter = 8/8″ = 1″. T12 bulb diameter = 12/8″. The T8 uses less energy than the T12, but puts out MORE light (counter-intuitive much?). Another benefit of the T8 bulbs is that they lose their intensity/brightness more slowly than the T12. You should be able to use the two types interchangeably in fixtures, and as far as I can tell, the T12s have no advantages, other than perhaps being slightly cheaper up front. While digging up this info, I discovered there is also a T5 bulb, which is even more efficient, but it costs substantially more.

      1. EcoCatLady says:

        Holy Moly! You are a veritable font of information! Thanks! 🙂

  2. Matthew says:

    The other downside of the t5 bulb is that it is extra narrow and has a different pin arrangement at the end, and thus requires it’s own kind of fixture to fit the pins and to diffuse the light. On the whole, I’m content with using T8s. I’m planning to add another light fixture or two to my setup, and plan to stick with my T8s for that as well.

Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s