Introduction: Self Regulating Container Garden
The Self Regulating Container Garden is ideal for anyone who wants to have a garden but is not in a place where they can cultivate a permanent space, as well as someone who is unable to regularly care for their crops. For example I rent and move about once a year so I can't afford to cultivate any permanent space of land, and the only place with sunshine where I currently live is the roof, which can only be accessed with a ladder. So I want a garden but it needs to be portable and it has to be somewhere I don't want to check on every day.
Before I start, a caveat: these aren’t exactly no work, no water. It’s just that you do all the work when you initially build these things, periodically check the main reservoir, and from then on the regulate themselves. But initially it’s a few hours and around $100. (Next year’s goal is to experiment with cheaper supplies. This time around I just wanted to see if it would work, period).
The reason I made these is because I had previously used lindsaytorte’s Dearthbox: A low-cost, self-watering planter with a lot of success with green beans, peas, chives, carrots, and bell peppers. Only thing is I moved to a tiny house with a tiny yard with a tiny strip of sunlight, so I had to do something else.
I found Kingnemo’s instructable for a system of buckets that are hooked up to a centralized water bucket, thusly eliminating the need to water the individual buckets on a regular basis. But his instructable has a lot of steps on how to retrofit a toilet ballcock assembly to make it work, but I simplified it be starting off with evaporative cooler float valves and skipping all those steps.
The benefits of this system is that it takes the guesswork out of watering; the soil wicks it upwards and absorbs water as needed. All you have to do is keep the main reservoir bucket watered, and even then you could check on it once a week or less.
The drawback is that it takes awhile to build them, maybe a few hours, and this time around it cost me about $100 for 5 buckets. But I could have easily saved $30 by using cheaper soil baskets (green drain gates, and I suppose if you use them year after year the cost of the investment dissipates.
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Step 1: Supplies and Tools
Supplies (for 5 buckets):
11 five gallon buckets from Home Depot ($2.34 each) (not pictured)
1 bucket lid ($1.96) (not pictured)
1 bundle ¼” rubber tubing (around $5)
5 1/4" Evaporative Cooler Float Valves. I bought mine from IdealTrue Value Inc for $2.90 each.
40 #6-32 x 3/4" machine screws w/ bolts and cap nuts (around $5)
5 drain gate (around $6)
5 tube to female pipe adapters w/ brass insert (around $4)
1 set Rubber Packing Sheet ($3.99) (not in picture)
5 brass inserts
Tools: drill; handheld Dremel will suffice.
pliers, or a leatherman tool
Step 2: The Float Valve
Take the plastic floaty part off of the float valve and cut the wire to shorten the valve so it will fit in the bucket. I dabbed a tiny bit of plumbing glue when putting the floaty back on the wire to seal it and prevent floaty from filling with water. I don't know if that is essential but it felt like a good idea.
The precarious thing about the float valve is that you need to shorten the arm so that it will fit in the bucket but still give it space so it can float without being pushed down by the top of the soil bucket or wicking basket. Yet it still needs to allow the water level in the water bucket to be high enough that it reaches the hanging wicking basket.
Step 3: Step 2: the Soil Bucket
Take one of the buckets. This will be the soil bucket. Trace the drain gate around the outside bottom and cut that shape. I just used my dremel to cut it, but maybe you have a preferred method. The reason this is traced into the corner is to give the float valve space to float without hitting the soil basket (drain gate).
Drill tiny holes along the top of the gray square a few inches from the bottom of the upper bucket lip, 8 per bucket, evenly spaced out. The reason for this is to lift the soil bucket slightly higher than it normally would be so the floaty has space to do its thing. Put the screws in, tightening the nut to keep it in place. You can add the little caps here to keep it from stabbing you in the future, but it’s not really necessary.
This bucket is now done.
(below left: bucket with hole. Below right: basket in hole. Observe screws near top of bucket)
Step 4: Step 3: the Water Wicking Bucket
This part may be hard to explain because I didn’t measure anything, just used landmarks on the bucket. Cut into the warning part of the bucket so that the hole is just big enough so the pipey part of the float valve can fit in.
Place the soil bucket on top/inside the water wicking bucket to see how they fit and where the bottom of the soil bucket is, and drill little air holes just barely under that. Really just barely, because if you drill them too low the water will leak out of them you and will have a perpetual water waste machine.
To be honest I'm not 100% these little holes are necessary. My thought was the wicking basket would benefit form having air as well as water available to it, and that if I had these I could more easily test the placement of everything else, ie if water is leaking then probably the floaty arm is being pressed down by the soil bucket. This is my first run, so it's still a little experimental.
Next, repeat steps 1-3 for as many planting buckets as you plan on building. Periodically test them out to make sure they work, because there's a delicate balance here between working perfectly and leaking water all over the place.
Step 5: Step 4: the Main Water Reservoir
Take whatever the main bucket is going to be and cut a hole (I used a dremel) just barely large enough to put the tube to female pipe adapters through. Repeat for as many buckets as you will have. This should be towards the bottom but the placement does not have to be precise.
You're going to want to cover this bucket after you assemble and fill with water for 2 reasons: to keep bad things form getting in and to keep the water from evaporating too quickly.
Step 6: Step 5: Assembly
Take all these parts wherever you’re going to assemble them, and then put together. Make sure to cut little squares of rubber and insert to assist in waterproofing. Cut the tubing the length you want each bucket to be from the reservoir. connect tubing-to-pipe-adapter, brass insert, and tubing as shown in the pictures.
The first time around I evenly spaced the buckets on the roof because I didn't know how heavy the would be and how much weight my roof could take but in the future I'd like to arrange them more attractively and less pod-people-y.
Step 7: Troubleshooting, Future Plans for Improvement.
Prior to planting I tested the buckets for leaks by hooking it all up and filling the reservoir bucket, and tightened bolts accordingly. Also I made sure that they didn’t leak through the air holes. 2 buckets did, so I replaced the buckets and re drilled the holes a tiny bit higher, adjusted the float arm on another.
After I tested for leaks and filled them with soil, I watered from above for about 2 weeks just to get the seeds started. If I had germinated and started the seeds indoors that probably would have been unnecessary, but I noticed that all of the soil in the bucket was well saturated except the top few inches, almost like it formed its own mulch layer. I just wanted to give the roots a head start. Some my seeds seemed to have disappeared (I think nearby birds ate them) so some of my garden was started from seed and some plants ended up being purchased already started from the Farmer's Market.
Since my buckets were on the roof the soil was susceptible to scattering from wind, so each one ended up getting a little sunken, with the soil level a few inches under the lip of the bucket. It didn't seem to harm the plants.
All-in-all this was very successful. As mentioned, I think it could be done more cheaply by replacing the drain gates with something similar, maybe old tupperware containers with holes drilled in them. Another idea is to make a burlap sack a little taller than the buckets, and line the soil bucket with that, including pulling some of the sack (with soil inside it) through the hole in the soil bucket, so it rest in the water and wicks the moisture upwards that way. Home Dept sells large squares of burlap for $3, you could either sew those to the right size or probably just find old rice bags and use that.
Next goal is to make it more aesthetically pleasing, maybe by placing the ugly plastic buckets inside a more attractive pot (still with a hole drilled in for the tubing) and arrange them in such a way so you can hide the reservoir bucket. Or, next year I'm thinking of making one large trough instead of several buckets, still with one centralized watering reservoir. Maybe I can hang it from above like an IV line from an iced tea jar. Who knows? I welcome pics and comments form people who have done similar.