Fluorescent Lighting for Plants
Seedlings require a lot of light; more are lost to lack of light than any other factor. Even a good south facing window will generally not be enough light in the spring to grow your seedlings. The sun doesn’t shine every day, and won’t provide direct light for enough hours in the day at that time of year.
Sunlight contains the full spectrum of light which plants use for photosynthesis, and that’s the selling point of specialized, full spectrum light bulbs used for growing plants indoors.
But plant lights can be expensive. Are they worth it? Or can an inexpensive fluorescent light be used to start seeds and grow plants with good results?
Fluorescent Shop Lights to Grow Plants
I purchased expensive full spectrum lights years ago. They worked just fine, but certain parts of the spectrum would burn out before others. Even though they were still producing light, they ended up being no better than a regular fluorescent bulb.
The technology has improved, but for the past 25 years, a regular fluorescent light is all I have been using to start seeds and grow plants with great results. So why spend the extra money for plant lights when they just aren’t necessary?
It’s funny how we can second guess ourselves, though. Several winters ago, I took a trip to Stone Barns Center for Food and Agriculture outside of NYC to tour the farm, and take a class taught by James Carr of the NY Botanical Gardens and author of Gardening and Landscaping the Natural Way.
I asked Mr. Carr what type of lights he uses to start his seedlings. You guessed it – he uses plain old fluorescent lighting to grow plants. Why did I feel a need to ask when I was using those lights with success?
Fluorescent lights give off little heat, so they can be placed very close to the plants without burning them. Keeping the lights close is, in fact, necessary to produce stocky plants.
Hang the fluorescent light with chains that can be adjusted. And be sure to keep the lights just an inch or two above the seedlings. Just keep raising them as the plants grow.
It is important that the fluorescent lights be left on for 16 – 18 hours per day for healthy seedlings.
Light quality drops dramatically near the ends of fluorescent tubes, even new ones. So it’s best to keep the seedlings at least a few inches away from the ends of the bulbs. If you have older tubes, and they are getting a bit dark near the ends of the bulbs, this is a sign they should be replaced.
So to answer your question, yes, standard cool-white fluorescent bulbs will work just fine for starting seeds and growing plants.
Do you start your own seedlings indoors? What type of lights do you use?
More Organic Gardening Posts You’ll Love
Starting Seeds Indoors for Your Organic Garden
Your Seeds Aren’t Germinating: Here’s Why
How to Compost Weeds the Safe Way
Lasagna Gardening: the Best Way to Garden
Using Wood Chip Mulch in the Vegetable Garden
How to Grow Pumpkins: From Seed to Harvest
To learn how to build a garden that builds healthy soil, be sure to check out my eBook The Art of Gardening: Building Your Soil. You really can become a better gardener, and you really can grow healthy, nourishing produce. It’s all about the soil! Click here to buy now.
© Depositphotos.com/[newlight] – Terms and Conditions
Thank you for visiting Learning And Yearning. May "the LORD bless you and keep you; the LORD make his face shine upon you and be gracious to you; the LORD turn his face toward you and give you peace." Num 6:24-26
Monica says
I am so glad I ran across this post today! I have my seeds started and they are under just regular florescent lights. Just last night I looked at grow lights wondering if I should go ahead and buy t hem. I decided against it due to pricing and to just wait and see how my seedlings do. I think I’ll just stick with what I have.
Susan Vinskofski says
That’s so great! Just be sure to keep the lights very close to the plants. 🙂
Ingrid Griffith says
In the 90’s I attended Penn college in Williamsport Pa. The teacher told us to start plants use one cool white bulb & 1 warm white florescent bulb in your fixture . This provides full spectrum lighting without those pricey grow lites .
Susan Vinskofski says
Hi Ingrid! That’s a common recommendation, but I personally haven’t even done that. 🙂
Ted says
I got a 2 foot fluorescent light made for growing seedlings at Home Depot I think it was only about $18 it work really well as long as you keep the light very close to the seedlings
Jak's Beanstalk says
Great post! I use regular flourescent lights to start my seeds as well and have had great success so far. It’s always great to get it confirmed though!
Susan Vinskofski says
Yes, that’s how I felt when I asked the instructor at the class I was taking. 🙂
Cano says
How long do I keep the light on? All day? 8-16 hours then off ?
Susan Vinskofski says
The lights should be left on for 16 – 18 hours per day.
sher says
they do work, but the best secret is a heat mat under your tray. I’ve had tomato seedlings up within 3 days with it. very much worth the $
lester stocking says
thanks for the info. I started seeds with regular bulbs last year and found that u must keep the lights close to the seeds. mine were tall and didn’t do well. I read about growing some plants inside during the winter. I have tried starting cabbage, spinach, broccoli. I bought plants the third week of January and so far they are doing fine. do you have any other suggestions. thanks
Susan Vinskofski says
Yes, Lester, that’s correct. The lights need to be kept close to the plants and moved higher as the plants grow. It’s also helpful to fertilize them with fish emulsion. Follow the package instructions for mixing, and then add water so that the fertilizer is half strength.
lester stocking says
by the way my plants are in my garage with wood heat. I used garden soil, peat moss, and vermiculite as the soil for the plants. this year I am going to do square foot gardening due to my age and equipment I have available to use. I have always done a big garden but feel I can do a better job if I get the garden closer to my house and be more selective as to what I grow.. we live close to the amish so some vegs. I can get from them to can and freeze like corn, carrots, and some kinds of tomatoes. my sq. ft. garden will be used mostly for greens. what type gardening do you do
Susan Vinskofski says
Lester, I build lasagna gardens and have had wonderful success. Here’s how: https://learningandyearning.com/2011/04/20/lasagna-gardening/.
Erin @ Natural Wonderer says
I’m so glad to read this! We are starting to grow fodder for our goats and chickens, and we are planning on using fluorescent bulbs. I was thinking it would work, but now you have verified that. Thanks! (visiting from the Homeacre Hop)
janet pesaturo says
Thanks for sharing on Mtn Woman Rendezvous. I don’t always start my own seedlings, but when I have, I have always used plain old fluorescent bulbs. Results have been fairly good.
Nancy W says
Great post, I’ve never tried ordinary lights to start my seeds. So god you shared your post on the HomeAcre Hop, hope to see you again tomorrow. – Nancy The Home Acre Hop
Sandi Derby says
I just found your website and I’m thrilled to death! I’m going to start making the newspaper pots later today! I started lasagna gardening last year with good results! Thanks for such an informative website! Looking forward to learning more, and saving more.
Susan Vinskofski says
Welcome, Sandi!! Glad to have you here.
John Baker says
Hi Susan,
This is my first year trying to start my own seeds inside. I have been reading all kinds of information on what other people have done. I used a home made heat mat (rope Lights) idea from Internet, to start my seeds, worked great! Then I took shop lights and attached two fixtures together that now gives me 4 bulbs per finished hanging light. I set up my lights over wire shelf racks in our walk in pantry. I have three shelves, 4″ long and 2′ wide for my starter plants each with it’s own light above on chains. I started with 2 cool white T8- 32watt and 2 soft white T8- 32 watt . My plants did OK but very slow to grow, I just bought 12 new bulbs 32 watt T-8, labeled Daylight (6500 K). They are a lot brighter and I hope they will help grow a little faster? I can’t seem to find the color range for these bulbs, will they work or should I go back to the cool white and soft white mixed? I don’t want to kill my plants. Please advise
Thank you,
John
Susan Vinskofski says
Truthfully, John, I think either will work just fine. Go ahead and use the daylight ones and see if you notice a difference. The ticket, though, is to keep the lights very, very close to the plants – to the point where they are almost touching them, and then raise them as the plants grow.
Charlene says
You can get a broader light spectrum (more similar to sunlight) by using one warm and one cool fluorescent bulb in your shop lights.
Noella says
Admiring the time and effort yoou put nto your website and
detailed information you offer. It’s great to come acroes a blog every once in a while that isn’t the same old rehashed material.
Wonderful read! I’ve bookmarked your site and I’m adding your RSS feeds
to my Google account.
Ted Young says
For purposed of seed starting, can “cool white” LEDs be considered the same light as “cool white” florescent?
Susan Vinskofski says
I’ve never researched LED lights for plant growth, Ted, so I’m sorry to say that I’m not really sure. I suspect that a google search will help you to find your answer. Thanks for stopping by!
R.A. McLain says
I have been having a problem with my tomatoes in my greenhouse. I constructed a large greenhouse with screen last year, because I have been growing organically for years, and thought I could stop the tomato worms and birds or insects from getting my tomatoes, but the tomatoes did poorly and were few and mostly small. I use heirloom seeds every year. Over the years I have had big tomatoes and lots of them. One year, before I built the greenhouse, I wrapped each tomato, not tomato plant, in thin row cover cloth. I sprayed with Bt, but still had to pick worms off the plants. This year, I put two round grow lights in there and the plants themselves are looking ok, not great, but the blooms are all dropping. I haven’t had one tomato yet. I then put two fans in there thinking it was too hot, and nothing yet. Do I need a fluorescent light bulb?
Susan Vinskofski says
Hi! I’m afraid that I have no experience at all with greenhouse growing. I hope you can find the help you need; thanks for stopping by!
Chuck says
Maybe they are not being fertilized by beas etc.
Chuck.
Christopher Jennings says
I know you are supposed to place the florescent bulbs as close to the seedlings as possible. My concern is the heat coming off the bulb. Please advise. I’m using t12 grow lights.
Thx, Christopher
Susan Vinskofski says
Hi Christopher, I have both T12 and T8 bulbs and have had no problem with either type keeping them very close to the plants – usually about 1″ away. Thanks for stopping by!
Christopher Jennings says
Thank you, that will make my wife very happy!
Ken says
I have a large set up of grow lights in my basement that I bought many years ago. I am going to add a couple more lights this year, because I have so many Gerber daisy seedlings. I have been looking at T12 shop lights, because they are cheaper. I have grow light bulbs that will fit them. After reading all of these fine posts, you have confirmed me to go out and purchase them. Thanks!
Terry says
Really new to indoor growing. Should the lights be left on 24/7 or do you need to shut the off to give the plants some darkness as well?
Susan Vinskofski says
Hi Terry, The lights should be left on for 16 – 18 hours per day.
Terry says
Thanks Susan. Excellent site, keep up the great info!!
Anonymous says
Good article! I’m starting tomatoes from seed for the first time this year, and am simply using a couple of 40W fluorescent bulbs. They’re very old (I’ve ben in this house since 2004, and they’ve definitely been here longer) but they still work – and they work great! So far, the tomatoes seem to be doing very well – no need to buy any expensive grow lights!
Jamie says
Hello, what bulbs do you actually use like we have some t12 40 watt cool white supreme lights that are like 2600 lumens. Is that enough light?
Susan Vinskofski says
Jamie, yes that is what I use with good success.
Jim Snyder says
I was worried that I may have been keeping my fluorescent lamps too close to my plants for normal growth, but after reading these posts, I guess I’ll move them closer. Thank you
Nellie Prinsen says
We read about the florescent lights, as we were wondering if we could start seedlings with them. thanks for the information, we will give it a try. Also thank you for the blessings you send along with your message. evert and nellie.
Susan Vinskofski says
You’re welcome, Evert and Nellie. The lights are great for starting seedlings.
Titilayo says
Hi,
I’m so happy to have come across your page. I have a very small space outside and plan to grow inside the house. I was wondering how to get grow lights because they are pretty expensive and will be double expensive considering that I am not in the US (I am in Nigeria).
I am going to do a rack with PVC and install the fixtures with normal fluorescent tubes but I need to ask:
How do I know a warm fluorescent from a cool one? And what wattage and kelvin are best? Can I place the light fixtures on both sides of the 3 shelf rack (that’s 2 light fixtures place vertically)? I am thinking of using foil around it for better light reflection.
Thanks
Susan Vinskofski says
Hi Titilayo, I don’t concern myself with a warm light and a cool light. I just use regular fluorescent bulbs from a local building supply store. I have both T12 and T8 bulbs. I would not place the bulbs on the sides of the plant because then not all plants will be the same distance from the bulbs. In addition, plants grow towards light and you will cause them to grow to the side. Placing the bulbs above the plants will assure that they grow upwards and that all plants are the same distance from the bulbs.
Titilayo says
And do I place a warm and cool tube side by side, and same distance to the plant?
GREG HEFFNER says
Hello,
I have recently built a grow chamber of my own design for starting my seeds for the vegetable garden. Although I have only recently finished it, and have not yet used it, I think it will work well. I am using 4 t8 48 inch fluorescent full spectrum lamps for the light source. I was wondering if you have any input on wheather or not to use the plastic diffusers that came with the light fixtures, or just go with bare lamps? Also, should I cover seedlings with a clear plastic lid during sprouting process for heat retention? I am using heat mats. I look forward to your response and input.
Very best regards
Greg Heffner
Amy says
Hi!! This is a little late, but I’ve used the plastic dallas containers placed on a radiator and have had good luck germinating seeds quickly.. The thing you gave to remember though is too pop the lid off or move them out once the seeds sprout otherwise you could get fungus or other diseases from the moisture!
Liz says
Will 20 watt T12 bulbs work or do I need 40 watt? Thanks