Easy & Cheap Auto-grow System





Introduction: Easy & Cheap Auto-grow System

About: Please support and share our mission; the Plant Doctor is a non-profit, open source online research laboratory specializing in electronics+plants. Our vision is to bring together nature and technology in a s...

hello world,

please support & share our mission;igg.me/at/smartplants


UPDATE: https://www.instructables.com/id/LED-Grow-Light-4/

UPDATE 1:https://www.instructables.com/id/Computer-aided-pla... 10/19/2014


I would like to share with you my simplest horticulture system yet. it can be made custom size - and as cheap as $7.60


if you read a little bit about plant training, you can actually grow very interesting trees in this system enabling them to get older with root trimming as well. in the picture we have a young citrus tree, looking very happy in it's new shelf


the system is 6Watts performing better than a 23W CFL (4x less wattage). it can easily be adjusted as the plant grows taller.



let's build..!


remember to vote ! ( top right corner of screen ) - thank you

Step 1: Plan + Parts

attached .pdf drawing (illustrator editable) can be used to cut the bottom part of the shelf from cardboard or any other equally strong material. -


adjust the dimensions accordingly to the size of the plant pot that will be used.


1W leds + led driver ($2.88 for 6W - $0.48/led +$2.80/driver for 6W)

dc fan + adapter (both from the thrift store $2 - $1ea)

automatic timer outlet (optional) - ebay $5.99

cardboard, sheet of metal, 4x chopsticks, metal epoxy -


drawing (building) on paper what you will be doing is a huge plus. I am just getting into the habit of this. when you actually start building, you realize that you've already built one before - maybe not physically, but nonetheless you will eliminate many mistakes/frustrations this way - keep everything simple & reuse "trash".


read my previous post on how to choose and match LEDs and drivers to get a better idea

Step 2: Build


I basically built a custom cardboard box to house the plant pot I chose. custom cut for the correct size..


if you do a good job cutting the cardboard, it will sit flat and be very sturdy with just a tiny amount of ducktape. you can also cut thin MDF board using a laser cutter.


use the 4 chopsticks as the pillars to hold the light up. since everything is extremely light, the carboard can easily support the weight. make sure the holes aren't too large, so the light can't slide down.


raise the fan up a little bit with cardboard pieces to enable good air-flow to the metal sheet.



all leds are connected in series and secured to the metal sheet with metal epoxy


here you can read an in-depth post about this exact setup



fans is connected straight to a DC adapter - make sure to read and match the power requirements of each component before connecting. voltage of adapter should always be lower than the voltage of the fan.!


both plugs go in to the timer outlet. to save more money, you can just set a daily reoccurring alarm on your phone, put the plant where you wake up, turn it on when you wake up - off before bed etc...

Step 3: Conclusion

don't be afraid to make the hole system smart so that it can e-mail you when the plant is thirsty or cold..


much more advanced than a bulb system. more efficient, and it's really obvious how plants like the difference.


I have and am making many similar systems each day. feel free to look around my profile - you will find many other similar projects.


thank you for your time and interest...

love & peace



*profile - facebook - website



    • Oil Contest

      Oil Contest
    • Clocks Contest

      Clocks Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    20 Discussions

    How large of a plant do you think this particular led setup would benefit and is there any formula you follow to determine like how many leds to what size plant?

    1 reply

    hello cwagner, a formula would be great for such a database and I actually have thought of such an idea before, just never got to it - so i really like your question. this particular setup can grow a plant for a long time IF you trim/train your plant to stay short and bushy. obviously if you put a tomato plant in there, it is going to fill up this space very fast and will require a bigger setup, but once again you can continue to tie it down every time it reaches a certain height. you will eventually have to add more LEDs. the reason why I can't give you a straight answer is because of what I've seen possible with such limited amounts of light. it's all about the angles of the light, how effectively you place them. the advantage of LEDs is that you can easily aim them close to the plant at different areas. the first link shows you how short you can keep a plant but still make it yield unreal amounts. the answer will also change per plant as well I believe. but to give a rough idea, I would say minimum 11x 1W high power led.s once the plant is 10" tall. but for example if you have a larger indoor citrus tree, this one here would require minimum 20 LEDs, maybe like a half moon dome over it covered with LEDs in side.


    you should also check this out, this system had 16 LEDs and works amazingly; https://www.instructables.com/id/The-Life-Seeder-ma...

    hope all this gives you a rough idea as to what I am trying to say.. let me know if you have any more questions.

    you are very welcome. thank you for your interest..! it's much simpler to put together than you think. go ahead, give it a try and share your work !!

    arduino + lcd schematics: https://www.instructables.com/id/Planterbot-The-Pla... & https://www.instructables.com/files/orig/FA5/RM0A/H... & https://www.instructables.com/id/Lighttemperature-S...


    LED lights schematics: https://www.instructables.com/id/The-Life-Seeder-ma... & https://www.instructables.com/id/The-Plant-Shelf-li... lights are very easy to connect. they are all in series, + to - to + to - to + until the end - to the led driver.


    let me know if you have any specific questions.

    I like your theory, I'm curious to see how this project turns out. Very good so far though!!

    1 reply

    you can check out the plant shelf, I have been using this for over 5 months now, no problems. I grew 3 lychee trees from seed under 11W - no fan (~3.5W per plant). if anything, this new prototype is working better. I could go as high as 15W in this much space, less than 2cm over the leaves. it's incredible, just make sure to cool them properly, which is still easier to do than CFLs. thank you for your interest.


    imagine a grandmother who knows nothing about plants - or the parents of a young child, curing their own cancer at home, making their own medicine, seeing exactly what goes into it - organic

    thank you polua, i'm actually working on making the lights go up automatically as the plant gets taller (it is going to take a while tho) so it can be totally automatic. ! stay tuned

    Very nice I'll have to build
    one now wb over heating??

    1 reply

    hello atomiuk, it does not overheat, if anything it is too cold, the fan is much stronger than needed for this application. you could easily use a 80mm fan instead of 120mm like i did (its just what i had) OR if you find a thick enough metal, you won't even need a fan, 1W leds dont get that hot, check this out - no fan and i've been keeping this on 12+hrs/day for the last 3+months; https://www.instructables.com/id/The-Plant-Shelf-li...
    thank you for your interest