Years ago, I started out with a sunny south window, but soon figured out that seedlings need a lot more light!  After extensive research, I purchased florescent shop lights since LEDs were expensive then.  They worked well.  But now LED lights have gotten less expensive, and are more energy efficient, so I switched over to new LED shop lights on my germination table (see pictures below).

What to Buy

First of all, you DON'T need to buy special "grow lights" for starting seeds!  If you are only growing small plants that will later go outside into your garden or containers, you don't need expensive grow lights.  High-powered, full spectrum grow lights would be needed if you planned to grow all the way to flowering and fruiting stage, (like if you wanted to grow tomatoes completely indoors).  But for starting seeds and growing them to a size to plant outside, a regular LED shop light will work just fine!  

What to look for when purchasing lights:  There are two numbers to look for when purchasing lights for seed starting -- lumens and kelvin.  Lumens is brightness and kelvin is color. 5000 lumens or higher is plenty for seedlings, and kelvin 5,000 - 7,000K (also called "daylight") will promote seedling growth.   You can find shop lights with these numbers at many different stores -- I have bought several at Walmart, Lowes, Sam's Club, and Harbor Freight.  About $20-$25 for a 4-foot shop light.

Distance from Seedlings.  The amount of light your plants get  has a direct connection to distance from your seedlings.  The closer you have it, the more light your plants will get.  

With my old florescent bulbs, I hung them 2-3 inches above the seedlings because the lights were not very bright. But I found that my new, brighter LED lights were burning the seedling leaves, so I raised them to about 12-15 inches.  You can hang several 4-foot lights on a wire shelf unit if you plan to have many trays of seedlings -- I use two LED shop lights per shelf.  Here's a good tutorial -- https://www.youtube.com/watch?v=MOFDmMD6HX0  Or construct a simple PVC frame to hold the lights if you want to put them over a table. See my pictures below - you can also find lots of ideas on the internet for how to build.

I have found it easiest to use some sort of chain to hang the lights, to be able to move them higher or lower as needed.  Most lights will come with a chain, and S-hooks work well to attach them to your shelves or cross-pieces.

You will need to experiment with your specific lights -- if your seedlings look like they are becoming tall and weak (we call that 'leggy'), they are most likely not getting enough light, so move them closer to the plants. And seedlings only need 14-16 hours of light a day, so be sure to turn them off and give your plants a rest at night (a timer can also help with turning them on and off).

Hope this helps!

Kate

The Garden Grandma