Build a Grow Light System for Starting Seeds Indoors
Do you want to start garden seedlings indoors? In order to grow healthy seedlings and plants indoors, you will need some supplemental light. Here is a simple and affordable grow light system made from easy to find equipment.
Growing plants indoors is an enjoyable project for any gardener. Whether you want to grow herbs indoors, start your garden seedlings, cultivate an indoor garden, or provide some supplemental light to your houseplants during winter, this inexpensive DIY grow light shelf will help you raise healthy plants.
Benefits of Growing Your Own Plant Seedlings
Growing transplants from seed offers a number of benefits, including:
- It is less expensive than purchasing nursery seedlings.
- There is a greater selection of seeds available in comparison to the standard plant varieties at most nurseries.
- It provides a little gardening therapy during the winter months when the ground is under a layer of snow.
In order to grow healthy seedlings and plants indoors, you will need some supplemental light. When I first searched online for growing stands for starting seeds indoors, I quickly discovered that they cost way more than I wanted to spend. A two-shelf unit with 4-foot fluorescent lights was well over $400. If you have the money to splurge on a grow light system, this 3-Tier Garden Grow Light Kit from Gardener Supply is a dream.
I was unable to afford such a unit this required some creative thinking to figure out a less-expensive option for starting seeds indoors. After shopping around, this is the DIY grow light shelving system I assembled. It has served me well for many years.
You can assemble your own inexpensive grow light system that will serve well for starting seeds indoors or growing an indoor garden.
DIY Grow Light System Equipment
Here is what you will need to set up your own grow light system:
I shopped around for a large wire-shelving unit that would accommodate 4-foot shop lights. I wasn’t able to find a large shelving unit locally, but I did find some 23-inch 3-tier shelving units. Two of these units placed side by side are the perfect size to hang two 4-foot shop lights across each shelf. The shelves are 13-inches deep and two standard seedling trays fit perfectly on each shelf. Plus there is room for two shop lights on each shelf if more light is needed.
These 3-Tier Shelving Units can be found in big box stores or online. Be sure to select units that measure around 30 inches H x 23 inches W x 13 inches D.
Shop Lights: The lights I use are your standard 4-foot shop light fixtures found in big box stores or online for around $30. These come with chains and a couple s-hooks. You will need to pick up extra s-hooks to hook the chain to the wire shelving.
Lights: Lights come in cool, warm, or full-spectrum. Full-spectrum fluorescent bulbs provide a balance of cool and warm lighting that represents natural lighting. Cool white bulbs provide blue/green spectrum while warm white bulbs provide red/orange spectrum. Full-spectrum bulbs were more difficult to find locally so I use the standard cool white bulbs. Most seedlings and greens do well with cool white bulbs. You can also mix and match a cool and warm bulb for a wider spectrum artificial light Just be sure to rotate your trays every few days so your plants receive the benefits of both as they grow. Check the packaging of your lights to be sure you are buying the correct bulbs.
LED Grow Lights: Also consider the new LED grow lights, which offer full spectrum lighting ideal for growing seedlings and plants indoors. The pricing on LED lights has come down significantly over the years. Be sure to select the correct sizes for your shelving unit.
Power Strip with Timer
Seedlings require at least 12-16 hours of light each day. I set my power strip timer for 16 hours on, then 8 hours off. The power strip with a timer is also commonly available in big box stores or online.
Plastic Gardening Trays
You will need trays or containers to help prevent water from dripping. These black growing trays measure about 20 x 10 inches and one tray fits perfectly on each shelf. These trays are perfect for seed starting using cell packs, soil blocks, or recycled containers. I like to double them up for a more secure tray that can be moved around without flexing. You can also use recycled produce trays or small plastic storage totes.
How to Setup Your Indoor Grow Light System:
- Assemble shelving units per instructions. Since these shelves are adjustable, make sure they are at the same level for both units.
- Locate your growing area near an outlet. Try to choose a place away from heavy traffic, pets, cold drafts, and excess heat. Place the shelving units side by side. I situated the shelves on a little used workbench, but they could also be raised up on a folding table to make it easy to tend to the seedlings.
- Hang your lights from the top and middle shelves using the chains and s-hooks. Plug the lights into the power strip timer and plug the timer into the outlet.
- Place your plastic gardening trays on the shelves, set your timer, and start growing seedling, and edibles indoors. Keep the lights about 2-inches above the seedlings and adjust as the plants grow.
Here are Some Gardening Tips to Get You Started:
- Using Soil Blocks for Growing Seedlings
- 10 Steps to Starting Seedlings Indoors
- 7 Herbs to Start from Seed
- Planning Your Vegetable Garden: Make a Seed Starting Schedule
- How to Grow an Indoor Garden
- 10 Reasons to Grow Your Own Organic Food
- Also check out this article on Expanding the Seed Starting Area to see how I increased my growing space by adding on to this DIY grow shelf.
I hope I have encouraged you to assemble your own inexpensive grow light system that will serve well for starting seeds indoors. Once you have your Grow Light Shelving System, it is fun to experiment with growing some edibles indoors during the winter months. Visit How to Grow an Indoor Garden to see what will grow under lights during the winter.You can assemble your own inexpensive grow light system that will serve well for starting seeds indoors or growing an indoor garden.
Grow Lights For Seedlings: When To Put Seedlings Under Light & How Much
Most homes don’t have enough natural lighting for seedlings, and trying to grow seeds on a sunny windowsill only results in disappointment and wasted time (and money!). But don’t worry, you don’t have to spend hundreds of dollars on fancy a grow lights for seedlings. I’m going to make this super easy for you!
One of the biggest frustrations new gardeners face starting seeds indoors is when seedlings grow spindly and weak. The only way to prevent leggy seedlings is to use grow lights.
But some new gardeners shy away from buying grow lights because they’re worried about the cost. And trust me, you definitely could spend a lot of money on plant grow lights.
But, for the average person, it probably doesn’t make sense to spend hundreds or thousands of dollars on fancy grow light systems for seedlings.
Don’t worry, you don’t need to spend a fortune! There are tons of options for different seedling grow lights out there, and it’s easy to find an affordable system that works for you and your home.
Starting Seeds Indoors Under Lights
If you are planning to get into starting seeds indoors, then you’ll definitely need some kind of a set up. It make things much easier (and a lot less cluttered) when you have a dedicated space for growing seeds.
This can be anything from putting your seed trays on the floor in the corner of the basement and hanging the lights overhead, or it can be a much fancier grow light system that you can buy or make yourself.
My grow light systems for seedlings
I have a great setup that fits perfectly in my spare bedroom. I bought a mini indoor greenhouse to hold all of my seedling trays.
It has a plastic cover that I can close all the way which is great for adding humidity around the seedlings.
I have lights that fit in there too, one hanging from the bottom of each shelf for the seedlings underneath (the lights aren’t in this photo though).
You certainly don’t have to get an indoor greenhouse like mine, you can use any type of seed starting rack that you want.
I sometimes use our extra garage shelves to add more space for growing my seeds, or your could buy a simple wire shelving unit if you want something more sleek looking.
If you want to start small, you can just buy a simple seed starting kit that come with a grow light and put it on a bookshelf or table (you could use either seed starting cells or peat pellets in this seed tray).
Why Use Grow Lights For Seedlings?
The first few years I tried growing plants from seed, I didn’t use grow lights. I am lucky enough to have a nice large south facing window in the spare bedroom, so I just set up a few shelves right in front of those windows.
This worked ok, but my seedlings were always thin and weak looking compared to the seedlings I saw for sale at the garden center.
Growing seeds near a sunny window
Things got worse for me once I started to experiment with different types of seeds, and it quickly became clear that my sunny window wasn’t going to be good enough (or big enough!).
In those early years, my seedlings were always weak and leggy, and many of them would just grow tall and flop over.
I discovered the hard way that seedlings never recover from this, and the plants don’t grow well in the garden either. I realized I was wasting a lot of time and money (and heartache) just to save a few bucks on grow lights.
Using seed starting grow lights prevents leggy seedlings
Benefits Of Using Grow Lights
That’s when I decided it was time to buy myself some grow lights, and I was amazed at what a difference it made!
Not only did my seedlings look fantastic, but adding a few grow lights meant I didn’t need to grow as many seeds because my seedlings were much healthier and stronger.
With proper seedling lighting, their survival rate was much higher, so I didn’t have to plant extra seeds to make up for that like I did in the past.
My grow lights definitely paid for themselves pretty quickly (since there was much less waste of seeds and dirt… and my time), and they continue to pay for themselves over the years.
Not to mention using lighting for seedlings have made my life much easier, and taken the frustration out of growing seeds.
Seedlings reaching for light
Benefit 1: Strong, Healthy Seedlings
The main benefit of using grow lights for seedlings is that your seedlings will be much stronger and stay more compact when they get enough light.
Proper seedling lighting is the the only thing that will prevent leggy seedlings, and thick, strong seedlings have a much better chance of surviving the transition to the garden in the spring.
Seedlings growing straight and thick under home grow lights
Benefit 2: Grow Your Seeds Anywhere In The House
Another benefit of using lighting for seedlings is that you can grow your seedlings anywhere in the house, you don’t need to worry about keeping them in a room that gets natural light.
This is a huge benefit for many gardeners, since most people don’t have huge sunny windows to grow seedlings in.
Plus you can hide your ugly seed starting setup away in a back bedroom, in the basement, or even in a dark closet if that’s the only space you have.
Without grow lights, it would be impossible for many people to start seeds indoors.
Do You Really Need Indoor Seed Starting Lights?
In order to grow strong, healthy plants, it’s super important to have the proper lighting for seedlings.
That being said, you don’t absolutely need indoor seed starting lights if you have a sunny windowsill, porch, or another super sunny space for growing seedlings.
I’ve started lots of different types of seeds in my sunny spare bedroom, and they survived just fine (though they were always leggy).
But if you ask me if the expense of buying a grow light is worth if for starting seeds. I’d say yes, absolutely!
Seedlings not getting enough light
If you’re just starting out and don’t want to invest a ton of money until you know you like it, then go ahead and try growing your seeds in a sunny window.
Just make sure it’s a south facing window, and the seedlings are as close to the window as possible. It never hurts to experiment and see what works for you, in your home.
But once you have a few seed trays going, and you know you’re hooked on seed starting, then I would definitely invest in proper lighting for seedlings.
How To Choose The Best Indoor Lighting For Seedlings
I mean… lights are lights, right? Nope! (but you probably knew it couldn’t be that easy) It’s very important to make sure you get the right type of lighting for seedlings, and all light bulbs are NOT created equal.
Just go to the hardware store and you know that now more than ever there are tons of different types of light bulbs to choose from.
Don’t worry, I’m not going to get super techie on you here (there’s enough technical information out on the internet already).
But it is important to understand that some bulbs (like regular incandescent light bulbs) are way too hot, and will only end up frying your seedlings.
Seedling lighting fluorescent bulbs
So what type of grow lights should you buy then? That’s easy! Your first option is to buy lights that are specifically made for growing plants indoors (plant grow lights).
You can find plant grow lights for sale anywhere these days, or you can buy grow bulbs and put them into a fixture of your choice (plant grow light bulbs come in standard sizes that are made to fit into any light fixture).
Another great option is just use standard cool-white fluorescent bulbs instead of plant grow lights.
When I went shopping for my very first set of seedling grow lights, I made my own using a standard shop light and fluorescent light bulbs. Here’s how I made my own grow light…
DIY Seed Starting Grow Lights
I’m always looking for ways to cut costs when it comes to gardening, so you can be sure my DIY seed starting grow lights are the most inexpensive option I could find.
This is a great option for beginners, and the supplies you need are readily available at any hardware store. Plus, you can swap out the bulbs and use the shop lights in your garage when they’re not being used for seed starting!
- 1 four foot (48″) shop light fixture
- 2 four foot fluorescent light bulbs
- 2 small chains (something like this one)
- 4 S hooks (similar to these)
Starting seeds indoors under lights
There’s no special assembly required for your DIY grow light, simply pop the fluorescent bulbs into the shop light fixture, and you’re ready to go.
Depending on the type of shop light fixture you buy, yours may or may not come with chains. But either way, there should be holes in the top of the light to put an S hook through in order to hang the light.
I like using small chains and S hooks to hang my grow lights because they make it super easy to adjust the height of the lights as the seedlings grow.
Use two of the S hooks to attach the chain to the light, and then use the other two S hooks at the ends of the chains for hanging the lights from your shelf.
If you want something nicer and easier to use than chains and S hooks, you can get a adjustable grow light rope hanger to use instead.
Using chain to hang grow light for seedlings
You can fit two standard sized seed trays end-to-end under one 48″ shop light, or four of them side-by-side (just make sure to rotate your seedlings on a regular basis so they all grow evenly).
If you don’t want to mess around with buying all the parts to assemble your own DIY grow lights for seedlings, or you’re not sure how to hang it, then I’d recommend getting a grow light system like this one. That’s a great option, and it makes setting everything up a snap!
Lighting For Seedlings FAQs
Whenever I talk about lighting for seedlings, or show off photos of my DIY grow lights, I get a lot of questions about them.
I already showed you how I made them above (FAQ #1), now I’ll answer a few of the other frequently asked questions I get about how to use grow lights for seedlings (ask your questions in the comments below the post if yours isn’t answered here)…
Seed starter grow light hanging from shelf
When Do I Put My Seedlings Under Light?
The answer to this one is simple. Your grow lights should be turned on (or your seedlings should be put under lights) as soon as the first seed starts to sprout.
Many types of seedlings grow super fast, and they will start reaching for the light as soon as they emerge. So give them plenty of light right from the start.
Put seedlings under light when seeds start to grow
How Far Should My Lights Be From My Seedlings?
Keep your grow lights 2-3″ above the top of your seedlings at all times. At first, your light will sit directly above (but not touching) the plastic lid on the seed tray.
Once the seedlings start to grow, and you take the lid off, then you’ll have to adjust the lights on a regular basis so it stays above the top of the seedlings (having a grow light system that is simple to adjust make this job a whole lot easier!).
Your seedlings should never touch the bulbs, so make sure to check on them often.
Rotate the seed trays daily if you notice the seedlings that aren’t directly under the light are reaching for light, or aren’t growing as well as the ones that are directly under the light.
Using indoor fluorescent grow lights for seedlings
How Long Should I Leave The Lights On During The Day?
Your grow lights need to be kept on for about 14-16 hours a day. Don’t leave them on 24 hours a day though. Like us, seedlings need to rest for a few hours each day.
So plan to give your seedlings 14-16 hours of light during the day, and then leave the light turned off overnight. Use an outlet timer to make keeping this schedule a snap, and ensure your seedlings get the perfect amount of light.
Seedlings grown under indoor seed starting lights
In order to grow strong, healthy plants, it’s super important to provide the proper lighting for seedlings right from the start.
Light is a key part of seedling health, and it will give them a good start to life. Plus you’ll find that it makes your job much easier in the long run. Weak, leggy seedlings are delicate and much more difficult to take care of than healthy seedlings.
If you’re new to starting seeds, and you want to learn everything you need know in order grow your garden from seed, then you should enroll in my Online Seed Starting Course.
Otherwise, if you just need a refresher, or you want a quick-start guide to growing seeds indoors, then my Starting Seeds Indoors eBook is just what you need.
More Posts About Starting Seeds Indoors
- Tips For Starting Seeds Indoors For Beginners
- Seed Planting Schedule: When To Start Garden Seeds Indoors
- How To Make Your Own DIY Seed Starting Mix (with recipe!)
- How To Fix Common Seedling Problems
Do you use grow lights for seedlings? Share your tips about lighting for seedlings in the comments below.
About Amy Andrychowicz
I live and garden in Minneapolis, MN (zone 4b). My green thumb comes from my parents, and I’ve been gardening most of my life. IвЂ™m a passionate gardener who loves growing everything from vegetables, herbs, and flowers to succulents, tropicals, and houseplants – you name, I’ve grown it! Read More.
Hinya De Pena says
when in the process of the seedling do you remove the humidity dome and the plastic from the greenhouse?
Amy Andrychowicz says
You can remove the plastic dome once the seedlings have grown tall enough to touch the inside of the lid, or have their first few sets of true leaves.
Are grow lights needed everyday (even when they are 5-6″ tall) until I transplant them out into my garden? Or can I just place them in a sunny window at this stage of their growth?
Amy Andrychowicz says
Yes, as long as your seedlings are indoors, then you should keep the grow lights on every day.
I purchased a grow light with LED light efficiency of 30W, LED quantity of 60 PCS. It has 6 different levels of brightness, would you recommend using a low or high intensity? I began with low, but I’m not sure whats better for leggy plants!
Amy Andrychowicz says
Humm.. I’m not exactly sure, I’m not familiar with those particular grow lights. If they didn’t come with instructions, then I would personally start somewhere in the middle, and then keep a close eye on the seedlings. If the seedlings look like they are reaching for the light after a day or two, then I would turn the grow lights up a few notches. If any of the leaves turn brown, then turn it down right away. If the seedlings look good after a few days, then you could either keep the light the same, or turn it up a little. I would just worry that the highest setting may end up burning tender seedlings.
Anna Kuzma says
Thanks so much! The seedlings have been taking well to the highest power setting, I’ve discovered the light’s not too strong and works well in my case.
Amy Andrychowicz says
Perfect! Thanks for sharing your results, glad to hear your new seedlings lights are working well for you. рџ™‚
My husband built me a hoop house last year. I have my seeds planted under grow lights in my house but can I move them to the hoop house during the day? My hoop house isnвЂ™t heated but in the day IвЂ™m hitting 70-90 degrees now or do they need to stay under the lights for a few weeks?
Amy Andrychowicz says
Yes, you can move your seedlings out to your hoop house during the day, as long as it’s warm enough for them. They don’t need to be under lights. However, just make sure they aren’t in direct sunlight, or it could burn their leaves. Also, make sure it doesn’t get too hot in there during the day, or it could cook them (I would vent it if it’s going to get above 90F). Read my post about how to harden seedlings to learn more about the process of getting them used to living outside.
Will I need another type of light bulb to have it on over night to keep the soil temperature around 80F?
Amy Andrychowicz says
I would not recommend keeping the grow lights on your seedlings all night long. It’s better for them if you give them some darkness at night, like they will get once they go outside. If you need to keep them warm overnight, then you could either run a space heater in the room, or place them on heat mats.
Jim Jozwiak says
I got the world’s cheapest LED grow light, with three light wands of red/blue LEDs.
I aimed it at about a square foot of seedlings for 24 hours a day, got very beautiful baby plants, but when I transplanted them outside, they quickly got little white spots on the leaves that I diagnosed as light burn.
I theorized that plant, although beautifully formed, lacked industrial-strength chloroplasts that could withstand the sun. In other words, the total daily radiation dose was right, but the radiation strength was too little.
So, I got another identical cheap grow light and only run both units 12 hours. I also added aluminum foil around the box of seedlings to get as much light intensity as possible. The lights are 6 inches above the soil. I transplant when roots start to come out of the bottom of the plant because if I transplant earlier, a couple of really hot days will badly damage the plant.
Amy Andrychowicz says
Awesome! Thanks so much for sharing your experience with using different types of light for your seedlings! Great information. I recommend hardening your seedlings before transplanting them into the garden. They can easily burn in the intense sunlight no matter how strong your grow lights are.
So to make sure I read this correctly, you are using just regular fluorescent bulbs? No true grow lights?
Amy Andrychowicz says
You can use either regular fluorescent bulbs or grow light bulbs for seedlings.
I started my plants a bit late this year and they are small. I do have a green house and can move them into there. But should I continue using the grow lights? If so, how long would I continue to do this? Is there a specific height? Thank you
Amy Andrychowicz says
If they will get full sun all day long in your greenhouse, then you can move your seedlings out there and stop using the grow lights. Once the seedlings have grown a few sets of their true leaves, you can start hardening them off outside to prepare them for the transition to the garden.
Alena Inman says
so my heat lamp broke today and i put my led light up is that okay i have auto flowering seeds is the led light going to effect my plant to where it dies??
Amy Andrychowicz says
LED lights don’t give off much heat, so you don’t have to worry about them getting too hot and killing your seedlings. However, if you are looking for something to replace your heat lamp, then LED lights aren’t going to help. I recommend using a seed starting heat mat.
Is a 2ft. 1 light tube suitable for seed growing in the same indoor greenhouse like yours
( like I have also ) would that be enough light??
Amy Andrychowicz says
It depends on how many seedlings you have growing in your little greenhouse. I use a 2ft light with two tubes hanging above each shelf of my greenhouse, and when it’s really full of seedlings, I still need to rotate them to be sure they’re all getting enough light. A light with only one bulb in it probably won’t be enough if you have lots of seedlings growing on each shelf.
phil beere says
While thr light is bright fleuros dont create heat??
Amy Andrychowicz says
They will create some warmth, but will not get hot and fry the seedlings like regular incandescent light bulbs can.
These are great ideas for choosing indoor lighting to start your seeds. I’ve never started my own (I’ve always bought the plants at the local nursery) but this would be a great way to delve into starting my own seedlings.
Amy Andrychowicz says
Thanks for stopping by!
What about temperature of room or soil??
Laura Bainbridge says
For temperature generally you want around 70 degrees F. No more than 75 but not under 70 IвЂ™ve found optimal
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