How to Build an Easy DIY Grow Light for Seedlings
Have you ever started your growing season with glee, only to be disappointed by spindly, weak seedlings? Don't give up! You might be missing one critical factor in your seed-starting process: light. You can fix that problem by building an easy DIY grow light for seedlings. Simple, affordable parts from your local hardware store will do the trick.
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This article was originally published on Stacie's old blog, The Petite Farmstead and updated to reflect current prices. You can find all of the other posts from that blog here.
Many veggies like tomatoes and peppers need to be planted from seed 6-8 weeks before your average last frost date, putting some folks (like myself) into February and March.
We only have about 9-10 hours of daylight in February. Not even close to the 12-14 hours of strong, steady light required by seedlings to get a healthy start.
Here's where our little project comes in.
The Dirt: DIY Grow Light for Seedlings
- Cost: About $150 for 1 shelf of lighting; additional lighting can be added later on (see costs & comparisons below)
- Tools Required: Rubber mallet (optional for assembling shelves)
- Difficulty: Easy
- Estimated Completion Time: about 30 minutes
Materials & Costs: DIY Grow Light for Seedlings
- One 48" wide wire shelf unit (L5-Tier Steel Freestanding Shelving Unit @ Lowe's: $74.98*)
- Two 48-inch long T8 fluorescent work lights with cords (Lowe's: $16.18* each)
- Four T8 fluorescent bulbs, 2 cool tone, 2 warm tone (Lowe's: $8.98* for 2 cool white bulbs and $9.38* for 2 warm white bulbs)
- 1 Digital timer ($12.99* for this digital timer on Amazon. It has a handy battery backup.)
- 1 Surge protector ($9.99* on Amazon)
- 4 S-hooks ($0.40 each* at Lowe's)
*Prices online as of 3/8/2018
Total DIY Cost
- 1 shelf of lighting (6 sq ft): About $148 or $25.04/sq ft
- 2 shelves of lighting (12 sq ft): $198 or $16.88/sq ft
- 3 shelves of lighting (18 sq ft): $264 or $15.18/sq ft
Compare to the cost of these commercial setups:
- 1 shelf of lighting (6.75 sq ft): $249 or $36/sq ft
- 2 shelves of lighting (10.6 square ft): $599 or $56/sq ft
- 3 shelves of lighting (18 square ft): $599 or $33/sq ft
Make the cost of your DIY Grow Light setup even less:
- Source shelving and other components on Craigslist.org or at garage sales; or try Freecycle.org.
- Watch for sales and coupons at Lowe's, Home Depot, or on coupon sites like RetailMeNot.com.
- Use sites like eBates to get cash back on your purchases. Right now, for example, Lowe's is offering 1% cash back. Plus, get an extra $10 when you sign up with eBates here and spend $25. I use eBates all the time and love it!
- Try visiting your local plumbing and electric store for deals on lighting and fixtures. My local Grover Electric and Plumbing Supply had the light fixtures on sale for $10 recently!
- Save on shipping by signing up for Amazon Prime or using the Store Pickup feature at Lowe's, Home Depot, Sears, or other stores.
Building your DIY Grow Light Setup
Step 1: Assemble & Install Your Shelf
Assemble your metal shelf, or if you already have one, install it where you want to grow your seedlings. My shelf is in daylight basement next to a south-facing window. Save the cardboard from the shelving box. Use it to line the shelves (to keep water from dripping on the shelf below).
Step 2: Assemble & Hang the Lights
Insert one cool bulb and one warm bulb in each fixture. Hang the lights along the length of one of the shelves, parallel to one another. Make sure the bulbs alternate warm-cool-warm-cool.
Use the S-hooks to attach the chains to the shelf above. Adjust the chains so they are 1-2 inches above your plants.
Step 3: Program Your Timer
Program your timer according to its instructions. The lights should be on for about 14 hours per day. I have mine set to keep the lights on from 6 AM to 8 PM, 7 days a week.
Step 4: Plug In the Lights
Plug your lights into the surge protector. Plug the surge protector into the timer. Plug the timer into your extension cord/wall outlet.
Step 5: Watch Your Seedlings Thrive!
This is the fun part! You'll notice that your seedlings will no longer be spindly and weak, but stout and strong.
I've since added another shelf of lights. The other shelves are perfect for storage for my seed potatoes, watering can, and other plants awaiting warmer weather.
What do you think?
How do you start your seeds indoors? Do you have a grow light for your seedlings?