6hrs vs 24hrs: How Many Hours of Light Do Seedlings Need to Thrive?

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Welcome back to the Mind & Soil Test Garden! One question I get SUPER often is how many hours should I put my Grow Lights on for so my seedlings can thrive? And while I have had lots of success starting seeds indoors, I didn't actually know how big of a difference the number of hours of light would make. So, in today's experiment I am starting 4 sets of identical seeds with 4 different amounts of light: 6hrs, 12hrs, 18hrs, and 24hrs. AND as a result of running this experiment, I am 100% changing the number of hours I leave my grow lights on for this upcoming season!
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00:00 Intro

[@Fulkersons]

Like others have said no matter what kind of light you have, they are too far away from the plant. Maybe that's another experiment to try. How many inches from the seedlings is optimal? Just a thought. Also the first part did frustrate me a bit. Unless the seed needs light to germinate the grow light doesn't matter, unless it's providing warmth. I enjoy your experiments, keep up the good work. Thanks

[@littlecountrykitchen]

Try experiment of height of the grow lights. Yours were too far away for broccoli which is why they were leggy ❤

[@MrQueerDuck]

In the first few minutes, watching each germinated seed counted had me clicking "summarize video." 16 hrs, got it, thx.

[@salimufari]

What I'm hearing overall is 16hrs is a solid sweet spot.

[@ambreewilliams6585]

I've been running my grow lights 24/7 over the past 15yrs during the seedling stage. I need my plants to get up and running so they can produce before the TX heat takes them out. This method works very well for tomatoes and peppers. I start seeds in January and I always harvest tomatoes and peppers in either April or May on a consistent basis. I got the idea for 24/7 lights from an old post on Gardenweb back in the day when someone experimented with it for peppers. I think it works for me because I'm not using full-powered grow lights. I use two 100w LED daylight bulbs in clip-on lamps. The light bulbs register at 5000K but only 1500 lumens, so that may be the reason I'm able to get away with doing 24/7 cycles during the 1st month. Plus my lights are very close to my plants - no leggy seedlings. Another advantage I've noticed is that I don't have to do a 'hardening off' period. I can take my tomatoes and peppers outside after a week of 24/7 lights and they don't wilt in the sun or show any signs of stress.

[@mannbat]

I run 16 on + 8 off, so glad to see an experiment that validates this as a good value. I have a suggestion for an experiment - 8 + 4 + 8 + 4. I've wanted to try this but don't have enough grow lights to make the test scientific. One other thing - you indicated the canopy growth, but didn't mention root development. Given many of us are starting seeds to transplant outside it would be good to know if one duration produced a better root mass than another.

[@MindandSoil]

I agree that a 16 on/8 off setup is a great balance and ooooo I like your suggestion for an experiment!

[@Cinematsic]

I've always wondered about this but haven't tested it myself! Thanks for sharing your awesome tests! ❤

[@MindandSoil]

Thrilled to hear this!! Stay tuned for the next experiments coming up!!

[@Cinematsic]

@@MindandSoil Definitely! Can't hardly wait 😁

[@cdscott]

You rock and your timing on this is perfect. I am starting seeds is about a week. Well done!

[@summerbeemeadow]

In a prior year, I made my own light fixtures using multiple 45W multiple-chip led arrays in each light bar that were made to duplicate the wavelengths and relative intensities that vegetables actually use. (They were available at the time by custom request from a company through Ali Express in China) These lights produced an intense pink/purple-hued light that included UV and infrared not normally accounted for in the definition of PAR. I found that the seedlings grown under these 'ideal' lights were shorter than usual with very thick, sturdy stems and lush leaves that were of darker than usual color. Overall, the resulting seedlings seemed to be a bit 'alien' in appearance, but did well outside, needing no hardening off re sunlight intensity. This was a fun experiment. It also resulted in my 'Karen' neighbor calling the police and reporting that I must be growing illegal plants in the intense pink/blue lights in my corner room. A trooper came to my door with a grin (he knew she was a problem) and we had coffee while he admired my plants. Fun times.

[@RichGardens]

You brought back memories of building blurple lights 20 years. Much easier now. Use white LEDs with a color temp of 3000K to 3500K for great results. Sometimes I miss the alien plants.

[@mandaryniak]

I needed a KZbin channel like this!!!❤

[@MindandSoil]

Thrilled to have you!!

[@heatherjolly8389]

This is my new favorite gardening channel. I'm obsessed!

[@MindandSoil]

LOVE YOU YOU DA BEST!! 🥳

[@Ando2k10]

When I set up my seedling starter shelves/lights, everything I could find about it said that 14-16 hours of light is optimal. This experiment was excellent, and has me excited to start my seedlings here in a week or two.

[@patrickvandervalk9622]

Great timing! Today I set up 4 shelves with grow lights and I will definitely use the findings from this lighting test. Keep on testing and sharing!

[@MindandSoil]

Fantastic to hear!! Yes definitely keep the plants closer to the lights than I did in this experiment, that was a good learning for me. And the intensity of the grow light makes a huge difference. I'm testing 5 different ones right now and can't wait to share those results with everybody!

[@FarmRanchHomestead]

Like so many others have said, I've heard for a long time that the distance to the grow lights needs to be reduced to prevent legginess. With the shelf unit you're using, you could set up different heights on each of the shelves to accommodate the various stages of growth of your seedlings. I have the same types of shelves and am thinking about setting up shelves that are roughly 8", 11", 14", 17", and 20" apart. With the lights attached to the shelves above, that would reduce the amount of available space by a couple of inches, so you might need to adjust these heights somewhat. That would allow you to move the plants as they grow, and put the taller plants on the shelves with more space. I need to purchase additional grow lights for my shelves, but when I do, it will allow me to rebuild my shelves in the manner mentioned above, and when paired with a timer for the lights, will allow me to set them to 16 on and 8 off as your experiment suggests would be beneficial.

[@priayief]

Your experiments are incredibly useful and informative for me. Thanks for your efforts. These kinds of experiments are never-ending. You have a hypothesis; you test and compare and then you go on to test the remaining variables. In this one, I learned that between 12 and 18 hours of light seems to be optimal (confirming prevailing advice). While that's not surprising, it's always good to see objective confirmation. Now it gets more complicated and more specific: Your type of grow lights as well as the distance your seedlings are from those lights. Doing an experiment for general interest is going to be a challenge. There is no "standard" grow light that your viewers use. And therefore, the distance of those lights from your seedlings will vary, depending on the particular grow lights you're using. I bet you've thought of this already!

[@timallen9818]

Brassicas will get leggy if grown too warm regardless of light timing or intensity. They prefer to be below 60F. Your data would be more useful if you could give a PAR value for your lights at the distance to the pots. Ideal for most seedlings is 200-300 PPFD. I use cheap Barrina LED grow lights set up exactly as yours are, and I have to elevate the trays so that the plants stay within 2-4" of the lights to get this PAR. Higher light intensity will yield a much sturdier seedling. My tomatoes are usually as thick as my index finger by the time they reach 1' tall. Thanks for posting your experiment. Definitely increasing my timing from 12 on/12 off to 16/8 for this year. Would love to see a similar experiment with varying light intensity at 16/8 timing.

[@Sirder]

What is PAR value thanks in advance.

[@timallen9818]

@@Sirder PAR = Photosynthetic active radiation. It's a measure of the intensity of just the wavelengths of light that plants can use for photosynthesis (400-700nm.) Lux and Lumens measure visible light, but not all visible light is useful for plants, so PAR is more useful when talking about grow lights.

[@Wellaskwhy]

Thanks man! I've always thought of this question. Love to see more videos from you

[@MindandSoil]

I'm glad it helped! Stay tuned for more experiments coming up!

[@anniemorrison1250]

As well as putting the grow lights closer, you might get less leggy putting the seeds deeper in the soil. Go ahead and eat those as growing greens. I grow broccoli sprouts too.

[@edslim718]

Really great work!!

[@MindandSoil]

Thx so much!! Stay tuned for more!

[@JBug_kit]

I personally love this, I'm glad there are still people making videos like this :) Oh, and for the broccoli leginess, you should check out the spacing and tempature, and they could also need a bit more water. The last time I grew broccoli, they normally go very limp when they don't get enough water in the right temp.

[@MindandSoil]

Thx so much for the kind words!!

[@JBug_kit]

I subbed to you, you're a good person

[@kirklarson116]

I love these experiments. I've seen other posters talk about light distance. My grow lights have 3 separate switches for 3 different colors. I just put all colors on. Might be a good experiment to see what colors are best.

[@carlderossi6497]

With 15 hours being the average natural light period i would say this test shows it's the perfect amount of light . And as far as light distance , the leggy seedlings show that it's more important in timing and not so much distance and intensity for more healthy growth . Proof that DLI is more important . But i would stick to the 15 hours and just measure the DLI from there to dial it to perfection . Interesting stuff , and thanks for the video .

[@katrinagarland5219]

I love your experiments... learn so much from them. Thanks again for your expertise and insight.

[@funsized924]

Thank you for this video. I couldn't understand why my tomato seedlings failed last year having them started in a window - it only gets a few hours of direct sunlight a day! Time to look into other ways of getting my seedlings light. :)

[@MindandSoil]

100%! In a few weeks I'll be launching a video where I test 4 grow lights and compare them to a window sill. Wait on buying a grow light until that video as it will end up saving you a lot of $$ as it's verrrrrry easy to buy a bad grow light

[@janew5351]

I think you need a heat mat to start tomatoes and peppers.

[@MindandSoil]

@@janew5351 I never use heat mats and actually find they cause more problems then benefits. Instead, I focus on ensuring the ambient temperature in the room is at least 75F/23C. This ensures not only that the soil is warm enough for them to germinate, but also that the ambient temperature is high enough for them to really thrive

[@slothisasin8240]

​@@janew5351 I don't use heat mats, I use soil blocks and LED for 16 hours/day in room temperature. It works well for me!

[@joyfulparadise]

Your experiments are so fascinating. I noticed that you grew each seed experiment in a 3 inch pot rather than plug trays. Is there a benefit to that?

[@IsraelEdenBeHereNow]

Interesring experimemt, and well done. Compared to my indoor starts, even your 12- and 18-hour starts looked very leggy to me. I use LED 6500K shop lights just a few inches above the seedlings from sprouting (rather than raising lights, I start with trays on scrap-wood risers that I lower as they grow), and the starts are lush with very thick and rigid stems, significantly shorter than yours. What do your grow-light instructions say about distance?

[@MindandSoil]

I can't recall off the top of my head, but I'm running an experiment rn testing 4 different grow lights and 2x of the other grow lights are performing incredibly well. After that one I think I might do one comparing different distances from the grow lights

[@IsraelEdenBeHereNow]

@MindandSoil correction, I don't know why I tried to spell the word fluorescent in my previous comments: I know they're LEDs! I've used them for several years, and I just ordered more on amazon. The price keeps dropping. They are pretty much disposable lights, but your last many years because they are LEDs. A 10 pack costs less than $80! They come in 5000 K and 6500 k, and I've gone with the 6500 okay with good results. With a little research on google, someone described 5,000 K as light in the morning and 6500k as stronger light in the afternoon. I don't really know about that. The brand is BBounder.

[@jerrybessetteDIY]

I use shop lights too. I also set up next to a window to get some natural light and use reflective insulation fabric to keep heat and light in.

[@surfingowl9646]

Love this video. Thank you. I wonder how different tenting the samples off, to prevent light bleeding would be ?

[@surfingowl9646]

As the plant wouldn't physiologically think it's night with that ambient leak imo

[@MindandSoil]

I actually did this in my upcoming experiment where I tested 4 grow lights. And I'm really excited to experiment with how close // far to keep plants from the actual grow lights!

[@bunaweed]

Beautiful experiment

[@MindandSoil]

Thanks so much!! Stay tuned for the next ones coming up!!

[@m-usman6041]

Thank you for such an experiment and with the experiment we come to know plants also need sleeping time, as written in gardening books.

[@Thehomested123]

Oh my goodness, your lights are way too far away from your plants! They should be an inch away and you move them up as the plant grows. Your lights are probably fine but they are just way too far away! As the plants get bigger you can move the light farther away but initially the lights should be right on top of the plants. Also brush your hands over the plants every day to strengthen them so they look thicker and less Peggy.

[@Thehomested123]

Leggy not peggy

[@mommabears993]

I came here to say this too. You have to have your lights within inches of your germination. Then move them up as the plants grow. But if you want to do the other experiment just to possibly get more equipment well then... Lol

[@world-karma9127]

Is this just for leds? I use t5s and keep the light about 10" above the canopy, short and stocky as I need...

[@grownfolksperspective2988]

I'd love to see this experiment again with the grow lights closer to the plants as usually recommended

[@VivaPonics]

Y’all I have my lights a foot from my stuff without leggy starts

[@AndrexT]

Very interesting results. I will wait for your Grow Light Video and then buy some. Do you lights provide some warmth as well? I remember you said you need around 70'F, we have a cool house.

[@nyomicasey]

What shelf did you use?

[@coastaldancemom]

I can’t wait to see your grow lights results!

[@TheTrock121]

Excellent work. I've often thought that 18 hours is better than the more common 12-hour recommendation.

[@waltnakonechny4548]

Dude, your lights are WAY too far from the seedlings. It’s not the lights themselves it’s the distance.

[@markhischier2750]

I put my $18 harbor freight led shop lights (5000 lumen) about 4 inches above the plant at start. Then move to 8 inches as they grow adult leaves. I've had lettus grow over three feet tall using these shop lights at 8-12 " (hydroponic vertical).

[@Wellaskwhy]

Yeah. I think that explains most of the results. The ones getting lots of light aren't that far apart in growth... shows that the intensity of the light is more important than the length of time of light they get

[@geradkavanagh8240]

From experience I've found chili plants like some shade during the hottest times of the day. Same for peppers. Had a couple of vegetable beds that went up to and under a very large tree in a North/South orientation. Peppers/chilies always gave best results under the trees shade. Asparagus grew well there as well. I could extend my lettuce growing period by placing them along the edge (lettuce tends to bolt when the temperature gets to hot, or too much sunlight hits them) and then plant the more sun loving crops in the full sun. I live on the Tropic of Capricorn in a semi arid area.

[@wilmot0]

I have seen in other videos that the lights should be no more than 2 inches above the plants and to also have a fan running to strengthen them.

[@sallygomez1044]

I have been waiting for this video since you posted the short. Love ve your experiments!

[@bethra.flowers]

In consideration for the leggie broccoli: Did you control for temperature? Brassicas need a decrease in temp after germination. Also light may need to be closer to seedlings as they grow (+/- 3 inches?).

[@MindandSoil]

It's definitely the light. I've kept temperature consistent and am running the next experiment where I'm comparing 4 different grow lights and the broccoli under the 2 stronger grow lights are absolutely thriving!

[@passportalwaysready]

Thanks for the video. Given how well the peppers and tomatoes did, I agree that temperature might be your problem. Brassicas get leggy if they are grown too warm,regardless of lights.

[@boneysworld]

Just found your channel. Brilliant mate .

[@kathrynmettelka7216]

Great experiments. Love empirical science.

[@MindandSoil]

thx so much Kathryn!!

[@gripplainandpractical1680]

what is the temp of the room? I'm figuring out seed mat use AND lights because my garage is 65 degrees in Ohio this time of year. More information on temps, please, underneath, surface of soil, and ambient air, all three.

[@MindandSoil]

Temp was around 75F/22C

[@romansvystun2631]

Thank you for all the experiments - they are a weekend treat. Broccoli like other brasicas won't grow well indoors - the temperature is too high. They require cold nights of about +8C. I never managed to grow decent seedlings of cabbage or broccoli indoors.

[@Miss.C.]

Yes please do a grow light experiment. Many of use the cheap Amazon that fit in the cheap 4 shelf greenhouses.

[@BernadineNewland]

When i lived in Alaska with 22 hour sunlight everything grew really fast. Tge grass we made hay from didn't have the protien and other nutrients in them though.

[@jacob1121]

Some seedlings require wind to develop normally, I read 30 seconds of a strong fan a day is enough to prevent leggy seedlings. Perhaps you could do a test with the same supplier for those broccoli seeds. Brushing them with your hand will also work, so be careful of that when doing the experiment.

[@MindandSoil]

It's definitely on the list of experiments to run 😎

[@merrilymreid]

Great idea about the fan!

[@MindandSoil]

Thanks for all the support y'all!! If you're wanting to have your best gardening season yet, it would be an ABSOLUTE honor to have you in GROUNDED. Click here to schedule a 1x1 enrolment call with me! 2ly.link/1xWPX

[@Cookies-i2f]

Thankyou for your hard work making this video. Now we know.

[@MindandSoil]

Glad it helped, stay tuned for more experiments coming up!

[@shurdar995]

Hey there. Thanks for the Experiment as usual. I would really like to see some additions. Light: First of all the PPFD is really important (light strength per day). It can be hard to understand at first but its about the light intensity x hours of light. Weak lights need to be switched on longer as strong lights for the same results. Please give us some Numbers there. Second: the roots. From my experience the "night time" is more important for interactions with the soil. Please show them too. Thanks for the great Work!

[@peterwong1231]

Great content! Did you use heat mats?

[@castletown999]

Very interesting! Plants differ in the amount of light they like. Some are sun loving other shade loving so wouldn't you vary the light times accordingly (or the light intensity). Also, I always thought that seeds should be germinated in the dark. I assumed that they only need light once they have leaves so they can photosynthesize. Another experiment perhaps?

[@surfingowl9646]

Rewatched this already ha. Love this type of experimenting. Germination, i would discount to seeds imo, as thats done in the dark/with seed energy. Grow lights maybe.. Or light leak. The plants are awake and searching for light that's not close enough. You should set a time lapse up. It will really show how the plants are cycling

[@MindandSoil]

Amazing!! Yeah I don't think the light/darkness has any impact on germination, but is obviously super important (and needs to be more than what they received in this experiment) as soon as they germinate. Because of that I'll start all my seeds under grow lights so that as soon as they germinate they're getting light 🥳

[@David-v4y4p]

Is there any intertest in looking at 10 - 20 hours?

[@thomgorman]

Did you mention anything about the amount and consistency of watering?

[@jSheapullen]

Did you mention temperature and if gave nutrients to?

[@rjstewart]

Having looked into this myself your 24 hour results are exactly as expected. The photosynthesis cycle needs a period of darkness.

[@MindandSoil]

Very cool to hear!

[@Mrs.Patriot]

I think the leggy ones need the lights to be only 2-3" above them, raising the lights as they grow. Very interested in the grow light experiment results!

[@Wellaskwhy]

Are they all getting equal amounts of watering?

[@beverlyr8152]

Awesome experiment 😊

[@MindandSoil]

Appreciate you!! 🥳

[@monikamona5271]

Very useful

[@curtiswiseman3178]

You have your grow lights pretty far from the plants. You might need to do an experiment with the lights at different heights, as well as adjusting the height to match plant growth. Excellent channel! I’m really enjoying watching your experiments.

[@MindandSoil]

100% agree!! Going to do that as an experiment coming up!!

[@viridian4573]

​@@MindandSoil Don't forget comparing the intensity of light (lumens) and the color of light used (warm, cool, red, etc)

[@carrolte1]

lots of hard work in this, so thanks. i would suggest a few changes to experiment. 1: Adjust lights so they are much closer to the plant tops. 2: thin seedlings to 2 or 3 plants per pot after germination so that each pot has the same amount of plants per pot. 3: Find a way to make sure there is no light pollution and the seedlings are not getting light from the other lights. 4: Don't count each seedling on video unless you do it in the voice of Count Dracula.

[@BushidoPhoto]

I always set my grow lights to 16 hours. It works well for me.

[@geraldphillips1533]

You need to add a fan to circulate the air to prevent leggy growth.

[@j.reneewhite915]

I use 20 dollar shop lights from walmart. The work great but I have to keep them about 4 inches above the plants. I'm sure it's different with legit powerful grow lights but my plants turn out great. The one plant you want to restrict light time to 10 hours are your onion seedlings. They trigger their bulbing process by length of day and your onions can get confused lol.

[@robertavillella6485]

The tomato and peppers had slightly thicker stalks at the 18-hr mark. I'm assuming that if left to grow for another 4 weeks, the tomatoes and peppers at 18hrs would look more robust and have a much thicker stalk.

[@potager365]

Hi, love your experiments. I grow on shelves 2" x 4" and I have 8 tubes per shelf and 16 Hour lights. I am considering reducing to 6 tubes but 3 is definitely not enough. Even if you have nice plants they are still leggy.

[@MindandSoil]

Definitely hang tight on upgrading things until I launch my grow light experiment results video as it's pretty incredible how big of a difference it makes!!

[@drewa4235]

How do you run a gardening channel and “experiment” without a par meter?

[@roryleitner1532]

Are these all long-day plants? Try this with short-day plants.

[@gigi77d60]

I didn’t notice you saying arugula differently until you said something. It’s just fine. 😊

[@patriciaveltre5875]

Great video, very helpful. I think I’ll go with 16 on 4 off. Thanks

[@MindandSoil]

Thrilled to hear it!

[@Miss.C.]

I direct sowed tomatoes in zone 6a and they did better and hardier than my starts.

[@MindandSoil]

Very cool!

[@midpavelvon9785]

Nice experiment, but I dont get why half time you count seedlings? Since when success rate of germination is base on amount of light? (definitely most dont need light)

[@MindandSoil]

I live and I learn! Definitely will take that into account for the next experiment! :)

[@summerbeemeadow]

Nice work!

[@MindandSoil]

Thanks brother!!

[@Gkgardening]

Brassicas will get leggy if grown too warm regardless of light timing or intensity. They prefer to be below 60F. Your data would be more useful if you could give a PAR value for your lights at the distance to the pots. Ideal for most seedlings is 200-300 PPFD. I use cheap Barrina LED grow lights set up exactly as yours are, and I have to elevate the trays so that the plants stay within 2-4" of the lights to get this PAR. Higher light intensity will yield a much sturdier seedling. My tomatoes are usually as thick as my index finger by the time they reach 1' tall. Thanks for posting your experiment.

[@2000BestXI]

Awesome video

[@MindandSoil]

Thanks so much!! 🥳

[@annhaan1195]

The time depends on the light and height of the lamp and the temperatur in the room aswell! So the better the light and the nearer it is at the plants, the less time they need over a 24hours period. If you are interested into the sience read about PPFD and DLI ! Some plants need exponentiall more light the higher the temperature is, mostly the coldhardy plants like kale, cabbage, lettuce and so on. and 24hours is stress for the plants, they need a downtime and there are studies and stuff, that shows that. With my old weaker light i needed 18 hours with 10cm height but with 20°C+ roomtemp even the 18h wasnt enough for cabbage, broccoli and lettuce and just "kinda okish" for pepper and tomatos ! My new good light only needs to be on for 12 hours and with 40cm height and even at 23°C its enough for lettuce and all the kale, cabbage.

[@5nation826]

Aren't all seedlings supposed to be about 2-4" below the lights at all times?

[@justinderaway3072]

I would try the plants distance to the light to see if that fixes the legginess

[@MindandSoil]

Yeah I have another experiment going right now comparing 5 grow lights and a) yes I definitely should keep them closer under that grow light and b) I'm going to be upgrading all of my grow lights to a more powerful one based on how much better they're growing! Stay tuned!!

[@BrightsideBounty]

Awesome experiment! Great results but Bruce Bugby might have a thing or two to say regarding the light. All of the plants in your experiment were exposed to 24 hours of light. Same goes for the light type experiment. In order to conduct a proper experiment you will need to black out the individual sets of plants. Also, those lights need to be an inch or two from the light hungry varieties like tomatoes. I agree with your conclusion. I have been growing since '96 and can tell you with certainty that vegging plants love long days and a nice rest. Plants perform certain processes at night that are crucial for proper development.

[@wannabecraftygrandma]

Love your videoes but the lights are just too high causing the legginess. If the lights are only an inch or 2 above the plant as it grows, the plant will grow stronger. Also put a slight breeze with a small fan and they get stronger :) That far away, they are reaching for the light vs putting energy into the roots, stems and leaves.

[@MindandSoil]

Yup 100% agreed - especially for these lights. I'm going to do a follow up experiment starting sets of seeds under lights at 3 different heights I think!

[@susand8816]

Shouldn't your grow lights be closer to the plants?

[@RichGardens]

Interesting test and results. Your plants for the 18 and 24 hour lights aren't getting enough nutrients and water. All your plants are leggy. I suffered the same results for years. Now I start my seeds under 24 hours of light. My lights are LED with a color temp of 3000K to 3500K. The amount of light is at least 30 watts per square foot. Lights are within a few inches of the plants. Starting mix is fast draining. A nutrient solution is used for watering. Keep up the great work. Can't wait to see your next test results.

[@martinroy9991]

Germination percentage is an average that is not really affected by the light time.

[@Bobby11]

Plants release co2 at night and Absorb it during the day, so maybe thats the issue with leaving the light on for 24hrs

[@julienfowler8274]

For the tomatoes, the 18 hour ones look stockier and greener than the 12 hour ones.

[@julienfowler8274]

I don't see why light would have any effect on germination rates, something that does is soil moisture levels and temperature.

[@Crumbleofborg]

I think the problem with the Broccoli is not the light, it's too warm for them. The other three are happy in 70F and higher. Interesting results, although not unexpected.

[@RoadToTheCup]

I'll be growing Cherry Tomato's, Roma Tomato's, Jalapeno's and Habenaro's, and other herbs, I'll be doing this on my balcony, I get ~9 hours of sunlight I face south What is the best soil mix. I live in Alberta my grow ZONE is 3b Thanks.

[@exhile3747]

16:30 16 hrs of light win, 8h per night

[@user-uy5md3fn6c]

I think your edit for 24 hour arugula is really the 18 hour arugula at the 16: 50 mark.

[@mpsorrentino]

The legginess is from the lights being too far away, they should start out a few inches away and move up slowly as the plants get bigger.

[@tylerrosicki5968]

18hr days are the most logical also. The days are longest in spring/early summer, when most plants are germinating.

[@JohnnyYeTaecanUktena]

Honestly some plants really thrive more on more light than what people really seem to think as Potato plants grow at insane speeds around 16 hour of light a day with at least 8 hours of night. But in general unless you see signs of sun damage or stress they can actually go a really long time absorbing light. Small problem though, know if your plant is a vining one or not as sometimes they look like they are getting leggy when they are starting to vine as seedlings, my snap peas did this and my Dragon Fruits did this. Also for cacti since they usually live in a desert or sub tropical place more light won't hurt it Unless you know specifically you can never go wrong with 16 hours a day and 8 hours of night, I only did that because Carolina Reapers are annoying to germinate if the light is not on for at least 16 hours and I noticed all the other plants around it was loving the longer light time. Now when i go to bed i do turn the fans on which is great for development but i did not know that as i just like hearing the fan noise since the walls are thin in the house and i can hear everyone else Anyways again if it looks like vining plants like Dragon Fruit or snap peas are leggy that is normal as they naturally do that, but specifically for Dragon Fruit it is completely normal for it to be leggy and look like it is going to fall over as it is a vining cacti so give it a trellis. Also like everyone said your light was too far away from the broccoli as it simply was not bright enough so they got leggy looking for light

[@potager365]

Hi again, what PAR of PPFD are you trying to get. I aim to get 600 PPFD, I use an app from my phone.

[@kb1236]

Your plants need to be closer to the lights to prevent legginess. Lower lights or raise pots. You want them about 2" from lights, adjust as they grow.

[@BrianM-44041]

Try 16hrs lights on, 8 hours dark. Optimal growth IMO

[@cherylmackowiak3728]

Temperature too high for broccoli, I think. Glad you did the test though!

[@jonquis07]

I just been using natural light 😅

[@flintstone19713]

You have the light to far from the plants. You should have done it 8 in away from them and when they came out 2 to 3 in away from light. And it depends on how strong the light is