What should I get for an auto watering solution?

Ok, I am new to micro-controllers and just recently started to read up about Arduino. I really liked this concept to everything. I planned on growing an herb garden for my new apartment and wanted to combine a simple project into it.

I am aiming to have an Arduino chip have some sort of sensor in the soil. This sensor would tell the chip when the plants should be watered. Once the water in the soil is down to a certain programmable threshold, it then would send power to a simple water pump (something like that of a fish bowl) this pump will then put out water over the soil until it gets to the maximum threshold.

This is something that sounds simple but i have no clue where to start and what i would need. I would like to keep a small size chip for this. I don't know what one to go with and what to use for the other parts.

Could someone provide me with more information on this? I am not worried so much about the software side of things as i am the hardware.


Herbs? Marijuana? Lol… How about vegetables? Anyways look for growduino or arduino garden. Bunch of people have made an arduino controlled garden.

Herbs in as cooking herbs lol. Thanks for that information, that is exactly what I wanted to do.

Just to get you started on some ideas…since I was thinking about this myself the other day. I’m kind of new to this stuff as well so these are very vague ideas.

I would start off getting an Arduino kit of some sort to mess around with and start with basic stuff like blinking led’s and pushbuttons…so you can get idea of how to write the software and see how the hardware works. That might give you a better idea of what you need to do.

Getting the water to the plants
You can either do a pump like you are thinking or a gravity fed (the tank is at a higher level than the plants). If you do a pump, you will need to control a relay to power the pump. If you are going to use an aquarium pump, you might want to do something like this controllable power outlet. However I am not sure an aquarium pump will provide enough head to get the water from the tank to the planter…it depends on how high you are trying to push the water. You might want to get a DC controlled pump and then your relay will be much simpler…you will still need a relay though.

If you do gravity fed, you will need to get an electronically controlled solenoid valve which will turn the flow on / off.

Metering the water
Then you need to figure out how to get the right amount of water with each watering…not sure on how you would do this. Either by monitoring the water level somehow or by monitoring the weight of the tank.

Detecting the moisture
Not sure how you would do this part either. Might be better to use a timer, but if your plants are sensitive to overwatering a timer won’t work.

e: well looks like someone might have pointed us in a better direction…

Found this: http://www.instructables.com/id/Garduino-Gardening-Arduino/step1/Obtain-Your-Materials/

Yeah i was wondering about the pump. How would i get it to lift the water. I also thought of a gravity fed system but is kind of inconvenient with area of my balcony and the apartment.

This guide from instructables is pretty good for it. The nail method with a voltage divider seems to be a good place to start with a moisture sensor. I am just trying to plan ways of making it sleek and small to not take up vital space on the balcony.

Maybe i will invest into a kit to learn more about Ardruino.

Can someone tell me if the nano kit is a decent kit or should i avoid the nano chip all together? Just considering this so i could create a nice water proof container for it.

Thanks for all the help btw.

Yeah i was wondering about the pump. How would i get it to lift the water.

I would use a "Little Giant" garden fountain pump, actually, with a lift capacity and flow rate for what you need. They aren't very expensive (for your needs, it shouldn't cost more than $20.00 or so), but they typically run off household voltage and not DC, so you will need to use a relay or SSR (solid-state relay) to control it.

The nail method with a voltage divider seems to be a good place to start with a moisture sensor.

I am not sure a nail would be best, unless you want to feed your plants extra iron (in the form of iron oxide - aka, rust). You might want to actually use a stainless-steel probe - maybe a short length of stainless steel tubing. Even better would be to probably hack an el-cheapo plant moisture meter that you can get at nearly any gardening store or nursery.


The Nano is a cute little package. I would recommend getting a Duemilanove or a clone of it. The chip in the Duemilanove is removable so you can take it out and put in another one or do other stuff like program new chips and all sorts of stuff. It’s a much more versatile package for prototyping - I would use the nano or something similar when I wanted to actually “install” my system and needed a small form factor.

tuxgraphics.org has an AVR based "remote watering and monitoring" project

Here is the link: http://tuxgraphics.org/electronics/200908/eth-flower-watering.shtml

My garden is a good size... I thought of making a solar powered system that'd run a sealed battery and operate a valve to turn on the water. So far I have about 40 tomato plants, about 40 different peppers, radish, seeral cucumber and squash plants. I hand water it daily and takes about 45 minutes not including picking weeds ;)

@Chris Do you have this indoors or outdoors? If you are doing this indoors would you mind showing pics of the set up. The biggest problem for me is that i live in a 3rd floor apartment and need to grow indoors or on my balcony.


I also have another question for anyone to answer. Someone was recommended that i get a starter kit. I was wondering if it would be ok to get something like this? http://cgi.ebay.com/Arduino-Nano-V3-0-Bare-PCB-DIY-/280527259058#ht_4927wt_1000 I would like to get practice soldering with boards and was wondering if this is a bad way to start out. I mean 2 bucks isn't bad. What else would i need for this?

Alot of stuff ;p. I'd get a rbbb or a whole new arduino w/ a 328. Adafruit has a kit with some goodies.

If its outdoors, and there is a water line available nearby, I would consider tapping off that water line (even if you have to trench and cover), then using the Arduino to control valve(s) off of that (using relays or SSRs - solid state relays); common sprinkler valving and a drip system would be perfect.