Instead of lowering my lights, I raise the flats. Some flats grow different under the same light, so I can lower a flat as they grow. Many things can be used under the flats, small boxes, old cake or muffin pans...works for me! Great information on the time, thank you! ❤

I hang those reflective emergency sheets around the grow light area. The light is reflected back and forth, plants grow strong and don't lean. Can get at any dollar store for a buck.

Thanks Luke. Your timing works for me. My setup has four wire shelving with four single strip meds of 5000 Lumina each.set to highest length. I use silver reflective sheet film around the shelving which magnifies the brightness. Works great for this small back yard gardener. The wrapping also acts as a small green house elevating room temperature slightly to assist growth. Love learning to grow from seed, so over plant and gives extras to family, friends and neighbors. It is a good bonding event we can all smile about. Thank you Luke for your info so I can bring joy in my own way..

Side reflectors do make a big difference. Plants in a reflective wall grow tent will get more light across the length of the plant vs. just shining straight down. also consider turning your plants from time to time and adding/removing stands to move your plants closer/further away from the lights as needed.

I'm really grateful for you, Luke. My main problem with most gardening resources is that they assume we know some basics that I personally did not know, as someone who was basically never around any gardeners but really wanted to learn. You're really great at explaining in layperson's terms all the little hows and whys that those other resources don't. The "whys" also make it easier to remember what you teach us. So, many thanks. :)

Always good to find out what works for other people. My indoor plants are in a grow tent. I have two 600 watt, marine full spectrum led lights. I like them because I can grow with all blue/white leds and not get the too much light leaf burns. I try to keep the lights around 4" to 6" above the plant tops. I set my timer for 16 hours on to grow plants that are short and very dense. When I want blooms I shorten the day length to 12 hours per day. The inside of the grow tent reflects the light to the lower leaves to keep them full. Now out in my old greenhouse the plastic is not really letting in the full intensity I need for vegetables so I hung some cheap four foot led shop lights. They are a couple of feet above the plants but they are just there to add to the natural light levels from the sun. They are on a 12 hour on schedule. They've increased grow speed by close to 100%.

I'm growing kale indoors this winter. 12 hour on/off cycle under a 4 foot shop light is working out very well.

Great comments. Lighting is often experimenting…taking things slowly…watching how your plants react.

There's lots of variables when growing indoors.. if your plants are growing tall and spindly chances are your lites are too far away, if the top of the plant is curling up and dying the lite is probably too close, a fan running on the plants help hardening off seedlings and is a good idea to run all the time ,, Nice post Luke!

Thanks Luke! I've watched past videos and it's always nice to get a refresher right before I need to do seedlings again! Don't give in to the pressure to give a hard number! Stay strong! You give us knowledge and that gives us power - we can take any light from anything and apply it! Thanks!😆

I am on the Michigan- ohio line, and have been learning more about seed planting indoors every year. I built my first greenhouse two years ago, last year built a larger one and transplanted my plants into the greenhouse when I think it is safe from frost. Before that I had always bought all my plants and it was over 200.$ I new I had to do something different.

Thank you! I like the advice of seeing how your plants respond to the grow lights. I just have house plants, but they all started suffering as the days got shorter. I'm setting up grow lights to fill in for the time the sun isn't coming through the window. They come on about an hour before the sun rises for just a few hours and then off. Then they come back on an hour before sunset and stay on for 4 hours. If my plants still struggle, I might leave them on for the entire day.

Luke it's very pleasing that you answered one of the questions I had about grow lights. I remember telling you what happened to me and how I fixed it. I had 2 tiny Roma tomatoes that I never transplanted. So I rolled the dice and transplanted them under my grow light. They are growing like crazy. I win! They may mature before I get them outside this spring, but I will enjoy watching them keep growing on. Another excellent video Luke. May the Lord keep blessing you and yours. Love you buddy.

One thing to mention is that some long day plants shouldn't get more than about 12 hours even if they are further from the lights - the solution there is adding more light rather than longer so as not to trigger bolting or other physiological processes prematurely. Two things that this is especially important for are spinach and onions.

I am loving all this indoor info right now. I got a mini tabletop hydroponics kit for Christmas that you are helping me mess around with. 😊 My green stalks are sitting out in the freezing cold 🥶. Thanks Luke!

Like all things gardening, pay attention to the plant. I just lost my avocado to over "enthusiatic" fertilizing because well the soil was "depleted." I am praying it forgives me and returns after being moved and pruned...I should have just enjoyed how happy it was and ignored all of the "instructions." Oh well...

I have recently discovered your videos and am binge watching them. So helpful and filling in gaps of knowledge that I didn't know existed.

Thank you so much for this Luke, it's really timely for me as I'm setting up a new area in a tiny lean-to greenhouse to grow my microgreens as I'm not keen on them being on the house any longer. The reflective film idea is fab. I just pulled out some polycarbonate to attach it to when it arrives. In previous years I haven't used enough lights and so hearing they can't really get too much I am encouraged to buy more and attach them lower to the trays. 😊

I am glad you mentioned plants in Alaska regarding time with light on them. I have been running my grow lights 24 hours at a time for my leaf lettuce to see how things go and so far the results have been awesome! I have been adding some dead periods of a few hours here and there to not overwhelm my Oregano plants that are super tiny that I want/need to do well.

I have a KlimaGro (probably one of the last made) indoor greenhouse unit. I have always struggled with how high to set my glass shelf and have added extra grow lights beneath the glass shelf etc. Your comment about lighting is often experimenting is very true in my case and watching this video has given me more insight to be able to tweak it a little bit more as far as the time I am leaving the lights on for my seedlings. I wasn’t leaving it on nearly as long as you suggest for tomatoes and they seemed to grow fairly slow. Thanks for the fresh information.

You are such a great teacher. I have watched other videos about light that left me feeling confused and unsure. You really broke it down and made it feel comfortable. I plan to start peppers today, along with my cool season plants like broccoli, kale, etc. Wish me luck on the peppers as they have been tough for me in the past. Hoping that with your helpful guidance I can produce some strong healthy pepper plants this year 🤞

I appreciate the info. It's always good to review before seed starting season.

Thanks. That was awesome. Best explanation on use of grow lights and I've watched several Blessings to you and family, and much gratitude to you for all that you do to help us navigate growing our own food. Happy New Year. Namaste.

Hi Luke, Many thanks for all this great information. The timing of your video is perfect for my needs. Much appreciated!

Thanks Luke, and what great information about reflecting the light. I was wondering about the time because I’ve heard different times given by different people.

I greatly appreciate this video, which explains a lot about light time and conditions. Just moved from AZ to Utah, so growing conditions are very different than what I'm used to. Thanks so much, big fan, not just your videos but your seeds too!!

Since controlling all the variables I.e. light distance from plant, light output of bulb, light needs of individual seedling varieties, reflective qualities of walls, humidity of the grow room, even temperature of grow room - may be difficult for gardeners to control, I appreciate your comments on observing how the plants are doing, what the signs are of light deprivation, etc. This is going to be the only way most of us can judge how our seedlings are doing, so your experience with observing the expected growing habit of a plant and how to judge when something is going awry will be most appreciated. This does all come with experience, reading, vids, but it really takes, I think, 3-4 growing seasons to figure out the basics for your own plot. Or a grandfather to advise you. 🇨🇦

This was very helpful. Thanks!!!🌿

Great information Luke, thank you!

OMGosh! A coincidence you would upload this today! I have been wondering about this! Thanks for sharing!!😊😊❤

This makes sense. Right now I'm thinking of getting a grow tent but what I don't like about them is that you have to open it and close it to access the plants and they're expensive. Something came to mind that might reflect light really well. My idea is a big pyramid with a reflective surface inside. The point should reflect the light better than a square box. Not sure what I'd use to make one that size, but I'm curious what it would do.

Thank you, very very helpful! I have grow lights and they are too far from the plants.

Luke, seeing a video from you puts me in a good gardening mood. I’ve learned a lot watching your videos and grew some amazing lettuce high-intensity style. My sister got me some of your seeds for Xmas and I can’t wait to try out the complimentary salad mix that was included! Thanks for making these videos

That window of 10-18 hours is the main thing I was looking for, as I've been considering either getting a timer or just leaving my grow lights on constantly, so this gives me a start knowing I'll need to get a simple timer for my lights.

great info! thank you. very helpful- just got our lights put up! yay

Helpful explanation of how the grow light reaches each plant. Thank you! 🪴💡

Good video for newbies especially

When my seeds first germinate I star them at a 16-8 for light/dark . Once they get established about 2 weeks after germination I bring them down to around a 12-12 or to resemble more of a spring day in Indiana. Around the 4th week I also introduce a fan onto the plants to get them good air flow since they start to get a little crowded and get them to become more sturdy by trying to stabilize themselves from what they think is the wind trying to blow them over. I feel as if while the fan drys them out faster it also prevents mildew from starting and forces the plants to take up the water faster before the fan takes the moisture away.

Good info. I also like to use mylar blankets around my grow racks to reflect the light back onto my seedlings. Seems to help keep them warm, too.

I’m excited to try to grow begonias this year!!😁

Great video it was very informative and helpful!

Completely unrelated but I'm loving the integrated MIgardener shopping underneath the video. I need ALL the seeds

I wrap my growing shelves on three sides with those mylar emergency blankets. The fourth side faces the sun. I also find that the fans blow around more once hitting the reflective blanket. Also holds in the heat and moisture, so it is not lost in the house.

Spinach can thrive with only 4-6 h of light per day, I think, maybe other greens too? I grew up north of the arctic circle, and even if the temperature is perfect for growing spinach in the summer, it will bolt immediately cause of the midnightsun, and the light 24 h per day. ☀️😊☀️

Thank you for this information.

I have a set of grow shelves, which we've surrounded by reflective Mylar on hooks. My lights (2 LED grow light strips per shelf) are hung with skinny strips of velcro, so they're easily moved up and down. I have them all plugged into a couple 16hr timers. And that's for everything. Seems to work just fine. I raise the lights as the seedlings get bigger.

Great info!! Thanks Luke!

This is super interesting! I have a Moth Orchid that sits on a table next my coral reef tank and It has bloomed last month and then put on another stem and has 8 blooms on that one alone! 😮 I think the UV/Blue spectrum I am using for my corals, also seems to benefit plants. Which makes sense. Both cases (grow lights/reef tank lights) are to mimic the sun.

I've been growing red shiso indoors in just natural sunlight up around 46 degrees north and had problems with the plants flowering, which terminates the vegetative growing stage of the plant's lifecycle. I learned the hard way that they will go to flower if given less than 16 hours of light since they're obligate short day plants when it comes to flowering. There are so many variables regarding light that are plant-specific. It's hard to know what to even consider.

Im growing Coast Redwoods in a greenhouse. I have a grow light about 2ft above the top of the trees. I have the lights on a timer 7a to 7p. With a light meter I have determined the grow lights are brighter than an overcast sunlit day or in the shade but not as bright as sunshine. When it is a bright sunny day I wheel the trees outside. My trees are in growbags in a garden wagon. So far So good. In May they will go into the ground. !

LUKE! TRIFECTA and $2 SEED PACKS

Great video, thank you for all your advice.

I’m thanks for the good info. Just in time for me. Havagudun and have a blessed new year.

According to the Old Farmers Almanac starting today thru Sunday I can sow my onions seeds

In my polytunnels when used to extend seasons particularly late fall. My rule for commercial hanging grow lights down a 12ft row double row planting of peas or 24 broccoli plants in grow bags: Once sun hours fall under 12hrs the lights are on 2 hrs before sunrise. As the sun hours decrease to 11 and skies are cloudy the grow lights are on for 14hrs. Lights are within 24" of plants - raised inch for inch as they grow. For tabletop seedlings I maintain space of less than 8-10" above seedlings for only 8 hrs per day - also keeping similar seedlings under the same grow light distance/intensity . None are leggy and fertilizing at 1st true leaves I end up with lush vigorous starts. I use a high PPFD professional light that's dimmable. Watch your seedlings, they tell you what they need.

Good timing! I started some lettuce and decided to use more reflective ( tin foil ) stuff for better light. I want to avoid buying lettuce for good, I never use that much but still like it around.

Thank you for spreading knowledge 🤓 Checking for signs the plants give us are always the way to go! 🌱 Just a question pop up after what you said. So I shouldn’t leave the grow lights on for more than 18 hours? Why is that? You said that in Alaska they get over that amount of daylight at certain times of the year. How does that differ from the grow lights, when it comes to length of time? 🤔

Definitely a question I have always had thanks 🙂

I like the guidelines that you gave. All plants have different needs and all lights do have different output and colors of light. I probably have not been giving some of my plants and trees enough time under the lights.

Thanks . That helped a lot.!

Thank you for the threshold, that actually helps.

Thanks for your video

How does this impact onion seedlings? Should I plan to stay below their hours needed to begin bulb formation?

I'd like to see you address seedling problems under grow lights, like leaves curling or turning yellow.

I have tomatoes, peppers, malabar spinach, longevity spinach, turmeric and Roselle in my basement. All from last summers garden and doing well so far. Using grow lights of course.

Helps to use a par meter app to calculate the DLI and compare the plant’s needs to the DLI the light can provide based on the light positioning and whether or not you are using some basic light reflection materials.

The biggest factor for how well your plants are doing inside is lumens. Outdoor sunshine is over 100000 lumens. So basically, the more the better. You don't need special lights, you just need high lumens at a cool colour (towards blue) for starting seeds. For time, minimum 8 for growing phase of seedings. If you keep a full grown plant indoors and want it to flower - switch to warmer colour light (red) and 18 hours. The idea is to mimic nature.

My seedlings are in a greenhouse, so I only give the plants enough to extend the daylight to 14 hours per day! This is around the length of daylight during peak growing season!

It is a misconception that all of Alaska gets 24 hours of sunlight all summer long. Only the area above the Arctic Circle get 24 hours of sunlight for any extended period of time, and that isn’t even all summer long. The ground there is also perma-frost and nothing can grow up there except things like lichens, etc. Also, the sunlight gained, or lost, is around 5+ minutes/day depending on where in the state you live. The farther north the greater the increase/loss.

Really depends on indoor temperature where your grow setup is also.

Looking for video about starting seeds under gtow light (blue light) and how long those lights need to be on etc. Will need this video later.

Thank you

Hey Luke! Thanks for the tips. I've always wondered if I should try to mimic the day/night effect with my grow lights. I guess it's a variable answer requiring experimentation. But that's not my question. You mentioned having reflective surfaces around the plants. My first thought was to use aluminum foil. Then I got real and thought, would it be advantageous to hang those reflective survival blankets around my racks including around the open sides of my racks? Mine are stuck in a corner in my basement due to space constraints, so ventilation is already compromised, but I digress. Anyway, those blankets are quite reflective and very lightweight, but they would also block ventilation if hung on the open side of the racks. What are your thoughts?

I get discounted broccoli seed around September and grow microgreens. I over winter cayenne peppers. I can't grow basil fast enough.

T information. I was just 😮going to buy my first grow light

All that time is a fair amount of power. How do you compensate for putting the seedlings in a sunny window for a portion of the day? It is far less light, but it would off set some of the grow light time. If you have at least 6 hrs in a window then add in 6 hrs under grow lights would that equal 8 hrs?

I like to start in my cheap amazon 2x2 tent with 1 amazon led grow light in January then yhen planys get bigger and weather warms lil more in end of feb march they go into garage in a cheap 2x4 tent with 2 amazon led lights then after that outside when weather is right. I use 14-15 hours run time as a happy medium. I check to see how many daylight hours there will be in start of spring or when planting starters outside and mimic that. Happy growin everyone!

Great info as always. Reminds me, we can use some @Nighthawkinlight ultra reflective nano barium sulfate or whatever is cost effective similar reflective paint to use around the perimeter of the grow room. Not only reflect the heat back in the IR range, the useful light in the visible and I guess UV range. Excellent sir! Affirmation station and then way some, because that's what you do young man. 🙂

I just lowered my grow light close to a foot. The greens are located at a southern facing window. They get actual sun and a grow light. May put a smaller size light up. 4ft to 2ft. The 4ft overhang alot and 2 barely overhang if any

We light our homes with grow lights already, just need to change what you think of as a lamp. Then you aren't wasting any electricity or money, the extra light becomes soft indirect lighting for the room. There are places in your home you want light, turn a few of those places into growing areas. A high bay garage light (Thanks for the tip Luke) or small square LED pad where you'd have a tall lamp. A wide hallway and some T8 lights become hallway tomatoes or a nightlight near a bathroom.

10 hours minimum. Got it. Thanks, Luke!!

i bought all the mirrors i could find at yard sales and thrift shops and put the all over my grow room

thx

Luke,would 'emergency reflecting blankets' work good for my seedlings?

Thank you for this, I was unsure how long to leave my grow lights on for, the height etc. I'm growing, chillies, tomatoes, peppers, basil at the moment. I've got different types of grow lights so will no adjust them depending on what I am growiing.

I live in Fairbanks, Alaska. It might be light 24 hours a day, but the sun is on or near the horizon for most of the “night time” hours, so not much photosynthesis is occurring. Also, our last frost date is June (and we had a hard frost the first week of June last year) and first frosts happen in September so our growing season is super short.

What about covering your lights and plants with that heavy white /black plastic, would that concentrate the light Just in the plant area? Think i bought it at a hydroponic shop.

The light you use makes a difference too. T5 fluorescent are great for most seed starting and the light distance can be up to several feet. Ceramic metal halide are a great high intensity light that can be used on tall plants or plants that will stay inside. LED light quality is so variable research may be required before purchase. Cheap shop lights are great for most seedlings but distance should be kept around a foot. Great video, Thanks!

I've heard that onions with too much light become too leafy and dont grow as good of blubs (or something like that). Any input?

Watching your recent videos, its clear that they new indoor potting system is for outdoor use only...

I'm trying to figure out how far apart my grow lights need to be? I'm not talking about the distance between the lights and the plants, I'm talking about how far apart on the parallel my light bulbs should be. My lights are Barrina T8 LED grow lights. 2' long, 20W, 2500 LM and 5000K. I'll be upsizing my new seed starting shelving unit and will be using Barrina T8 LED bulbs that are 4' long, 40W, 5000LM, 6500K. These will be fully height adjustable but I'm not sure how far apart these bulbs should be? Thanks for your help and suggestions

How long does it take to get seeds? I ordered a bunch and was curious how long?

What about the onions I'm starting? I don't want them to bulb when they are little. I know that they are very daylight hours sensitive.

I'm trying to see if I can grow alyssum as a houseplant. I've got tiny sprouts now. We'll see what happens.

In the wild there is no 16+ hours of direct sun every day especially here in the UK, people say put plants on the window sill, it has to be south facing right? what about if it's directly south, no sun rise or set areas

I have 5400L and 6500K 40W shop lights. I will put 2 lights per shelf in my garage. What is the recommended distance from the seedlings? Also once they start growing after the seedlings stage what is the recommended distance then? How can we tell which veggie plants need more light? I plan to grow some inside in a sunny window and also a weaker grow light I purchased.

Sunlight is 98000 lux per m2. I have 8x2200 lux grow lights. This only provides 18% the light of sunlight. That being said, I still get good result with them on for 10 hours a day keeping my poinsettias and a bay laurel alive. I may add another 8 lights and extend the time. BTW - the Wi-Fi wall warts are very convenient in metering the time the lights turn on.

What type of grow lights do you have?

Is Reflective Mylar Films helpful? I currently have a white wall trying to ensure I am successful.

Thanks if buying from a box store make certain they cover the light spectrum plants need and realize shop lights at box stores don't have that spectrum.