# Self watering elevated garden box



## j10c3y25 (Jan 8, 2014)

So my girlfriend has been getting into gardening lately, and I wanted to do something nice for her (plus I get to build stuff). I came across the square foot gardening method of using raised boxes, and that's where it started. "Honey, I will build you a garden box," couldn't possibly be that simple for me, so in my usual WAY over the top style I had to amp it up about fourteen notches.









Here you see some [very] rough sketches of the box concept, along with my materials list, both of which ended up changing along the way. Dimensions are 2'W x 6'L x 34"H, so you can reach the entire span of the box from one side, as well as stand comfortably without leaning while you work. The box will be self watering, in the sense that there will be an internal water reservoir that will only need periodic filling, and the soil will only pull up what water it needs through the wicking process. The base of the box stands at 14" off the ground, and the internal box depth is 16 3/4" after subtracting the thickness of the frame and bed. This gives me room for my layers as follows: The box will first be sanded and treated with linseed oil to protect it, then I will install landscape fabric or burlap to protect the plastic from sharp edges, a layer of 6mil plastic to make the inside water proof, another layer of fabric, the PVC pipe system, a 4" layer of gravel as my wicking medium, another layer of fabric, 10-12" layer of soil mix, and then mulch on top. I will also be adding some trim and decorative pieces to the top, and incorporating a level indicator into the watering tube. I got lots of good information from this website http://www.resilience.org/stories/2011-05-31/bottom-diy-guide-wicking-beds

Some quick math told me I would need 8 cubic feet of gravel, which will displace ~60% of the water layer, giving me somewhere in the neighborhood of a 13 gallon reservoir. Using conservative estimates of weight per cubic foot of soil, water, and gravel, the total weight of my full box would be close to 1500 pounds. This means every square foot of box space must support 125 pounds since I was determined to make it elevated. Not only that, but it would need to withstand the outward pressure of a half ton of wet soil. GAME ON. If there is anything I'm good at, its over-engineering the hell out of stuff. I set my bar at being able to jump around inside the box with the intent of breaking it and it not budging an inch.









This is the completed bed support frame, the cornerstone of the whole box and my first real attempt at using any sort of joinery (if you want to count lap joints). It is constructed of 2"x3" studs, cut to 6' and 2' lengths, and lap joints every foot on center. The two outer most laps are on the opposite side, allowing the outside pieces to be flipped over. In this manner, even dry fit I can pick up the frame from any piece as it is completely interlocked. I wanted to finish the project with NO fasteners showing, so I predrilled holes along the inside of the bed frame to attach to the sides. Then I glued the laps together and placed a sheet of 3/4" plywood sheathing on top, drilling screws down and through the center of every lap joint.









The sides are just butt jointed together with 3" wood screws, and at this point are not attached to each other at all. Each level is just its own floating rectangle until the legs are attached.









Underside of the box, here you see the frame is hidden by being flush with the bottom side rail.









Here I have assembled all four layers of side rails and installed the legs. The legs are just 2'x4' butted and screwed to 2'x6' boards, but I used an oak dowel to make plugs and hide all the screw heads. I predrilled holes from the inside to attach all the legs, and fastened with 2.5" "high performance exterior screws". They had a 5lb box on clearance for $9, and they are far superior to the wood screws I was using as proven by a quick test. I screwed half of each kind of screw into a scrap 2"x3" and hit them sideways with a hammer. The SPAX construction screw snapped on the second light tap, whereas the exterior screw I was able to bend all the way over and then all the way back up before it snapped.

I put the box on the ground and romped around in it with all 200 lbs of myself and its solid as a rock...BUT!--I am not satisfied. As it stands, the sides can still be considered not attached to each other, all the downward pressure on the bottom frame is supported entirely by the screws from the bottom side rails into the legs. In order to remedy this I need to install some bracing vertically on the sides that is not in contact with the ground, then the load can be spread onto the rest of the fasteners on all the side rails into the legs, thus adding tremendously to the strength. I've got some leftover 2'x4' which I plan on cutting 20" lengths and putting at 2' and 4' on center on each side. After that I need to figure out what kind of molding and corner squares I want to use.

Hoping to get to the braces in the next couple days, then have it sanded and finished with linseed oil by this weekend. I haven't even started on the PVC system yet, I gotta drill a sh$$load of holes -_-

This may be more of a gardening project than a woodworking project, but I am building it with wood so I think it counts! I do wish I knew more about construction, I'm fairly certain I have used 100% more materials than necessary, and that you could most likely set a tank on this. But hey, all part of the fun I guess.

More to come...


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## Geoguy (Feb 22, 2008)

I like it. Nice and sturdy. The hard part will be moving it out to the patio when finished.


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## johnnie52 (Feb 16, 2009)

It looks really nice, but how are you planning to make it hold water and how much water are you planning on?


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## j10c3y25 (Jan 8, 2014)

johnnie52 said:


> It looks really nice, but how are you planning to make it hold water and how much water are you planning on?


That would be the layer of 6mil plastic I mentioned that will line the inside. With my gravel layer at 4" I should have somewhere around 10-15 gallon water capacity in the reservoir.


So anyways, I drew a couple sketches to see which way I liked better, a single piece in the center or two pieces at 2' intervals, and definitely liked this better.









Here you can see I have made good use of my 5 lb. box of screws.









The only thing left to do before finishing is some of the decorative pieces to hide these corners.









I'm thinking of trying to fashion some kind of pyramids or the like from all the scrap I have left to use at each corner, and also the centers where the brace meets at the top. I just don't know if I should leave it at that or put some kind of trim on the side rails as well, I can't imagine anything that looks right for some reason.


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## Pauley (Jan 21, 2012)

Very interesting...I'm looking forward to seeing more.


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## eepaul (Oct 16, 2013)

A 6mil plastic liner will very likely leak, especially with that much weight and the rocks in the reservoir. You dont need to get a really heavy duty 45mil liner, but hd and lowes sell ones that are less heavy duty and should work. The one linked should fit your box. Also, unless you plan on putting the rocks in very slowly one by one, you might tear (almost guaranteed to tear a 6 mil linear) your liner when pouring them in. I have pond in my apartment that is similar in construction to your box, and used a sheet of insulating foam as padding for the sides and bottom. You shouldnt need to pad the sides of yours, but I would recommend something more sturdy than just cloth as a liner. 
http://www.homedepot.com/p/Total-Po...ft-Pond-Liner-PVC12005/202278976?N=5yc1vZbx70
http://www.homedepot.com/p/Unbrande...ft-Foam-Insulating-Sheathing-754404/100572981


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## frankp (Oct 29, 2007)

A couple of comments... don't line your box with fabric, even if you use a heavier liner for water. The liner WILL leak at some point and then you've got wet fabric rotting against your wood. Also, linseed oil will only protect the wood for maybe a month or two outside. 

If I were building it, I'd use a sealant on the wood, either some marine epoxy or at the very minimum a spar varnish. I would also use a pond liner,which will be closer to 20 mil thick, generally. I wouldn't bother with "cushioning" the sides with any kind of soft liner, be it cloth or foam just because both are going to pull water from your system when the liner leaks. I'd also make sure I could move the thing easily, though now that you've built it full size that's going to be significantly more difficult. 

Also, I can't tell for sure but it looks like the hardware you used isn't likely to last submersion for very long. Something else to consider.


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## johnnie52 (Feb 16, 2009)

I know we are taking your hard work apart, but better it comes from us than from a bunch of water on the floor.

Its a good design, you just need to rethink how you're going to keep the water in it.


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## frankp (Oct 29, 2007)

Johnnie makes a good point. I should have also included that I really like the design and aesthetic of the thing. We've been bouncing back and forth about whether or not to build some raised gardens at our house. A design like this might really be a good compromise.

Your construction method is going to be plenty sturdy, too, which is always good for things that are going to hold as much weight as it seems like you're planning.


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## eepaul (Oct 16, 2013)

I certainly didnt look at it like taking your work apart, and hope my post wasnt construed that way. I have just built several ponds of my own, (Ill get around to posting my current one someday) and can almost guarantee that a 6mil liner will tear. The purpose of the foam on the bottom is to give the liner some leeway when you pour the rocks in. If you pour them in and the liner is just sitting on hard wood, again, it is almost guaranteed to tear. Even if the wood is smooth, the liner has pressure on both sides from hard surfaces. If you get a super heavy duty liner (45mil+) you dont necessarily need the foam, but those are pretty expensive and I think getting a cheap pond liner and a foam sheet is just as efficient of an option.


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## j10c3y25 (Jan 8, 2014)

Thank you guys for the comments, I have to admit at first I was a little peeved, but you made some valid points. I did need to rethink a few components.

I tested some sheets of 6mil plastic by dropping and stomping gravel into them, it made marks for sure, but no tears. Nonetheless, it would be near impossible to repair if torn, and I don't want to go buy expensive pond liner, so I found a solution. Multiple layers of plastic (its cheap and I have a big roll) alternating with layers of landscape fabric (like they make bullet proof glass). 4x6mil=24mil, works for me.

I found many instances of raised beds that are built with cedar or redwood and left unfinished, unlined, and can last for years (10-15 in some cases), which is why I chose redwood. I'm aware that it won't last forever, and I'm ok with it. I am, however, going to change to a food safe finish of food grade mineral oil/beeswax, because apparently boiled linseed oil contains some additives I don't want anywhere near my vegetables. It'll look nice for a while...and then it won't, we'll see if I'm not too lazy to apply a new coat to the outside when we get there  If you know of any food safe finish that will last longer let me know, but as I imagine, nothing will be very permanent and safe at the same time.

I don't understand how landscape fabric would rot. Its a synthetic, basically made of plastics  As far as I understand its much more susceptible to UV damage than water damage.

No one is submerging any hardware, and even if I wanted to it says guaranteed against rust for LIFE right on the box, certified by Rustoleum! Hey, its gotta count for something right?

I'm going to try my damnedest to get it done this weekend, between my physics lab report and trying to wrap my brain around this materials science class. Crystals! Everything is Crystals! It's terrible -_-


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## j10c3y25 (Jan 8, 2014)

I abandoned the post cap idea when I saw something I liked much better. Here is a dry fit of some of the pieces









Its just a 1"x10" pine board that was very symmetrical looking in grain pattern, so by sawing it straight down the middle and staggering the small pieces, it looks like it matches all the way around, even though only 2 corners truly match. It was going REALLY well until on one of the miter cuts my radial saw bound up and a fist size chunk of my corner snapped off. Its ungodly frustrating, I had to stop and build a straight rip jig for my circular saw earlier because I have no jointer, and then after tediously dimensioning everything perfectly this happens. I've rigged this up in an attempt to pull it back together, after it dries I'm going to try to put a spline in the bottom between the two pieces for a little extra strength.


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## eepaul (Oct 16, 2013)

Hey another physics student! What physics lab are you taking?


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## johnnie52 (Feb 16, 2009)

I like how your planning to do the top. :thumbsup:

Looking at how you are trying to fix the broken corner I noticed what looked like a large knot right at the angle. Pine is really weak at the knots and miter saws are not very delicate. I'm glad you didn't get hurt when the saw tore the corner and that you have developed a way to fix it. :thumbsup:.


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## frankp (Oct 29, 2007)

I like the top edge, it really finished it all. In reference to your cloth comment/question about rotting, I didn't see that you meant landscaping tarp. That wouldn't be too much of an issue and shouldn't soak up too much water either. That said, I don't see what you gain by using it other than expenses. It's not really going to protect anything or add any padding, though putting on the top layer to prevent weeds would be a good idea.

The redwood will look like it should if you don't bother with any finish or minimal finish. Again, the mineral oil and beeswax really aren't going to do much except cost you money. At most they will only last a month or two. If that's your plan, I'd just leave it natural with no finish at all and save your money. Like you said, it will look nice for a while and then it won't. (Although, I personally like the look of weathered redwood for outside furniture etc so I think it will still look good. Besides, it's a garden it people will (and should) be looking at the plants, not the container.)

I really enjoyed my materials science class, way back when. Where else do you get to build things and then break them just to see how strong they are?


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## j10c3y25 (Jan 8, 2014)

I got a lot done!

Here you seen the broken corner piece, the glue up worked so that was good.









I made these miter clamp jigs from a diy article on the internet somewhere, and then I used a chisel and some cut off strips to make splines to hold the joints together. My miters weren't perfect, partly because of the broken corner, and also I believe partly due to an issue with my fence which I haven't fixed yet, but no biggie. I filled in the gaps with some shavings/strips, and sanded everything flush, overall I'm satisfied with it.

I also put together the fill piping









There are about 100 holes drilled along the tubes near the bottom to allow even water distribution, and the piping increases the reservoir capacity by displacing some of the gravel.

I sanded the box itself, then put my glued face frame on top and screwed it down. Used the same oak dowel to fill in all the screw holes, then sanded everything flush and finished the whole project with butcher block conditioner. The bottle actually stretched pretty far, managed to get 3 coats out of it. Everything turned out great!























All that's left is to put in the drain pipe, level gauge, and line the insides, and I can get it filled up and ready to plant.


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## Priusjames (Jan 13, 2014)

It's looking good...I've enjoyed watching the build, thanks for sharing!


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## ssgtjoenunez (Jan 14, 2014)

This came out great! My wife has been looking to get into gardening and I had thought about doing above ground planters but nothing this nice (or tall!). 

She really wants to do some light vegetables and maybe some chiles. Either way I might be stealing some (or all) of this thread 

Nice work! I am really interested in the plumbing and how it all turns out.


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## frankp (Oct 29, 2007)

Agreed, the final solution looks quite nice. Good job.


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## ssgtjoenunez (Jan 14, 2014)

I was curious if you had thought about pre-drilling pockets holes in that top 2x10 so that the top frame could have been attached without the need to drill, dowel and fill. I've been thinking about making this for my wife and was thinking if I created pocket holes on the top 2x10's (before they are screwed together to make the frame) then I could avoid having to dowel and fill.

Also - any update on the plumbing inside the box? I am curious how you are going to check the level. 

Thanks!


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## j10c3y25 (Jan 8, 2014)

ssgtjoenunez said:


> I was curious if you had thought about pre-drilling pockets holes in that top 2x10 so that the top frame could have been attached without the need to drill, dowel and fill. I've been thinking about making this for my wife and was thinking if I created pocket holes on the top 2x10's (before they are screwed together to make the frame) then I could avoid having to dowel and fill.
> 
> Also - any update on the plumbing inside the box? I am curious how you are going to check the level.
> 
> Thanks!


I juggled a few ideas including the pocket holes, but I don't have a pocket hole jig and it would have been a pain to do . I see no reason why it wouldn't work, but I actually like the look of the dowels, and screwing in from above makes it seem more secure to me. The face hangs over the sides by 3 1/2 inches everywhere except for the corners and centers where it has some more support, but screwed in the way I have it I'm not worried about people leaning on it. Had I gone the pocket hole route I would have also made some triangular supports mounted under the frame and used those to attach screws from underneath, or something like that.

The plumbing is really not complicated, it's just a fill port to get water down into the reservoir. The more I think about it the more I realize it may not be necessary in the first place, just a straight tube to the bottom would accomplish the same thing lol. The touchy part will be getting the drain in correctly without leaks. I will be doing that this weekend so expect pictures soon.


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## Acercanto (Jul 9, 2013)

Very nice build!
For the drain, could you just use a siphon inserted into the fill tube whenever you need to? Sure, you'd lose the last 2 cups or whatever, but it'd be one less hole in your liner.

Acer


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## ssgtjoenunez (Jan 14, 2014)

j10c3y25 said:


> I juggled a few ideas including the pocket holes, but I don't have a pocket hole jig and it would have been a pain to do . I see no reason why it wouldn't work, but I actually like the look of the dowels, and screwing in from above makes it seem more secure to me. The face hangs over the sides by 3 1/2 inches everywhere except for the corners and centers where it has some more support, but screwed in the way I have it I'm not worried about people leaning on it. Had I gone the pocket hole route I would have also made some triangular supports mounted under the frame and used those to attach screws from underneath, or something like that.
> 
> The plumbing is really not complicated, it's just a fill port to get water down into the reservoir. The more I think about it the more I realize it may not be necessary in the first place, just a straight tube to the bottom would accomplish the same thing lol. The touchy part will be getting the drain in correctly without leaks. I will be doing that this weekend so expect pictures soon.


Thanks for the heads up! I have a pocket hole jig myself which is why I asked about them. I guess the dowels aren't a deal breaker but I had planned on making that outer frame a little smaller than yours so if I pocket drilled it I wouldnt be as worried about things being set on it or people leaning on it since there would be less material. 

For what purpose do you intend to need a drain? I mean couldn't you just not fill it and let the plants naturally soak up the water? I guess I just don't see a reason for it unless you plan on emptying it (though if its a stationary planter not sure why you'd do that?)...


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## j10c3y25 (Jan 8, 2014)

The drain is not a drain in the sense that you're thinking, I guess I should have called it an overflow port. It will just be a horizontal tube through the side the controls the full level of the reservoir. It can be adjustable if you stick an elbow on the outside but I don't think I will. Basically you fill until you see water come out of the overflow. In the event of heavy rains it also prevents flooding. If the water level raises into the soil layer then it can potentially drown the plant roots


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## j10c3y25 (Jan 8, 2014)

Got some stuff done today!

First I had to figure out what size sheets of fabric and plastic I would need, and what would be efficient considering the dimensions I started with. I decided I would do full layers and partial layers, so that the part with the water/gravel has some extra material. Installation involved liberal use of a staple gun, just don't staple through your plastic near the bottom since that's the part that NEEDS to be waterproof.








First fabric layer, cut slits at corners for easier installation









First plastic layer, your success with this part is based completely on your ability to wrap Christmas presents. The staple gun is your friend. Ensure that the plastic is fully seamed into the corners and edges or it will become load bearing and create a weak spot when the materials are added.









Trimmed all the excess over the top, and then taped 3 of the partial sheets of plastic together and installed. Taped into place for the time being, these sheets go 6-8 inches up all the sides, plenty of protection.









Next layer of fabric goes in, and then carefully bundle and fold the material back on itself, stapling into place every few inches allllll the way around. This is made much easier by clipping out the big wads of plastic in the corners.









The top edge is the only part that needs to look good, because the rest will soon be filled in. Just make sure in the way you stapled the sheets in that you can still peel back material to an extent to work with the overflow tube. The reason I haven't installed it yet is because I want to drop the fill tube and gravel into the container first. This will give me an accurate level for the top of the gravel, so that when I install my overflow I can bring the water level just below flush with the gravel. Gonna work on that tomorrow!


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## MT Stringer (Jul 21, 2009)

That looks really nice. If it were mine, I would take a jig saw and round off the mitered corners, then sand em smooth. They are going to jab you or her.


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## ssgtjoenunez (Jan 14, 2014)

Hey did you ever finish the planter? My wife is going out of town for Spring Break next week and I was planning to build this one for her as a surprise for when she comes back.


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## j10c3y25 (Jan 8, 2014)

Yes I did, sorry for not following up. Build it in a week huh...I don't think I couldn't done mine in a week, lol, maybe now that I've done it once I guess. Either way I definitely want to see yours when its done! Alright so here's all the stuff I've been to lazy to post.

So since this is a vegetable garden I want it to be in full sunlight, so I picked a nice spot in the yard and proceeded to dig, lay bricks, and level as best I could. I feel I could have done a better job of this...but I pretty much had no patience left and just wanted to be done. So this was good enough!









Throw in the fill tube









Next up comes the heavy lifting. 4 cubic feet of gravel = 400 lbs









This part was extremely satisfying, I don't know why









Now this part is another instance where I could have planned it better, I'm sure you can come up with your own improved system. It was a HUGE pain the way I did it, but hey, its a learning experience. Scoop away the gravel, peel back the liners until you get to the single liner against the inside wall. You want all the other layers clear because you're going to drill through the side with a hole saw. I found that my math for cubic feet of gravel was pretty much dead on and I probably could have drilled this hole before hand, but I wanted to make sure I had it in the right place. In retrospect, not that critical.

I found the most difficult parts of the procedure were: The hole saw set I had did not produce a snug fit for my 1" PVC pipe, so I used a smaller size and then manually filed away until I could barely muscle it through. Second, if the hole saw gets a hold of the plastic it won't cut a clean hole, it will just bunch it up and be a huge pain. You'll have to go at it with a razorblade or some scissors and make room. Don't be worried about your waterproofing, we're gonna make a patch next!


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## j10c3y25 (Jan 8, 2014)

So once you get your hole sized just perfect for your tube, and really you want it as snug as you can get, put some wood glue inside your hole and shove the tube through from the INSIDE. My theory here was that the glue would swell up the wood, and help to seal the hole against leakage to prevent rot. Pushing from the inside makes sure that the glue is not getting into our container, avoiding any possible toxin concerns. Get it into place quickly, it doesn't take long before it won't move at all.









Note, my tube lets water drip down the wood if its coming out slowly, but if its draining a LOT, like it did the first time before I got my screen worked out, it eats up the ground around the base and I have a big mudhole. Fortunately I've left enough pipe outside to connect for later modifications, and in Arizona we don't see a lot of rain, but plan accordingly for your climate and chosen spot in the yard.


Now take a square of plastic and cut a small hole in it, and you have a patch









Next you need your trusty tube of silicone. If you are growing food in this garden, make sure you get the one that says "food safe" on it. As with anything read the instructions. Mine said, hold parts together for 5 minutes, then let cure for 24 hours. I applied liberally, like legalize pot liberally.









Fiddle with it how you will until you're reasonably sure its waterproof, and once everything is cured (don't jump the gun, 24 hours!) put everything back in place and fill it up to test.









I decided to use the landscape fabric as my screen on the overflow tube, this keeps dirt and gravel inside but lets water out. I did not realize how strangely waterproof the fabric is if you have more than one layer against it, even with 1 it was dismally slow and I overfilled my box by a few gallons before I figured out the problem. I ended up cutting away most of the fabric by the tube, leaving just one layer, and then cutting some slits in that with a razor blade to make sure I didn't have that problem again.

Once you're confident of everything, lay the last piece of landscape fabric over the gravel. This piece is just the dimensions of the inside of the box, it keeps soil from falling through to the gravel layer.


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## j10c3y25 (Jan 8, 2014)

Next you just pour the soil in. For raised gardens they recommend a special soil mix that is now available at some of the big box stores. I found mine at home depot, it'll be called "square foot gardening mix" or "mel's mix" or something like that. There's still a couple inches left over for mulch to cover, but we haven't planted yet. Actually about to do that tomorrow!









For the level gauge this is pretty slick, and super easy. Pardon the crappy pictures I just went out and snapped a few shots in the dark. Basically you just get yourself a dowel and a ping pong ball. Drill a hole through both sides of the ball the size of your dowel. Insert the dowel so that it just comes out the other side, it should be snug. Once again use your food safe silicone and make sure to cover the openings well, let cure for 24 hours. Drill a hole slightly bigger than the dowel in the cap of your fill tube, drop the ball in the hole and put the cap on with the dowel through it. The ball will float on the surface of the water, leaving some amount of dowel poking through. Push the dowel down until the ball bottoms out, and then cut off all but the last inch or so of dowel showing. With a freshly full reservoir, look at the level of the dowel and mark your gauge. I did mine like a traffic light, green is full, yellow in the middle, and red means empty. You can see it from across the yard, and it works great.

Here it is removed








Holding it up so you can see the colors








And here its sitting showing its current level








One last fail to report. The pine board I chose was of poor quality, with even more warping than I realized. I figured the glue and screws would hold everything in place and it wouldn't matter, but it is cracking along several places. Its not that big a deal really, but its annoying considering the work I put into it. Either way this was a learning project, and I think I've learned a lot. Next I'm making a small cabinet with a wide shelf to go in front of the window for her seedlings, lets see how I do with dados, lol.

Oh, and to end on a good note, it WORKS! I was worried for a bit, and thinking about how much I sunk into this project, but it WORKS and I am satisfied. I left it for a week after filling it, and then went out to check the moisture in the soil. The top feels dry, but if you peel back even a couple inches its moist and warm, so its wicking perfectly, and it feels like you're scooping air the soil is so fluffy. I'm extremely excited about growing vegetables in this thing, I'm feeling confident about having a big haul in a few months!


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## tseitz11 (Dec 19, 2012)

If I understand this correctly the water will reside in the rock bed, below the level of the soil, and the plant will pull the water up through the soil as need, is this correct?


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## j10c3y25 (Jan 8, 2014)

Yes and no. The water does reside in the reservoir in the bottom, in the rock bed yes. The adhesion/cohesion forces of the water cause a capillary action that move it up into the soil. I've recently learned more about this, apparently its called matric potential; and at the point where the matric potential meets the gravitational potential it creates a perched water table. Meaning if the container mix is too heavy it would basically be permanently waterlogged at some level. The plants in the container can only root as deep as the perched water table level, because any lower and they would be in sitting water, which is no bueno. As the plants use up the water that is available to them in the soil, water from the reservoir continues to rise so that equilibrium is achieved; keeping the soil evenly moist as long as the reservoir is not empty. Here is an informative link if you are interested.

http://oregonstate.edu/dept/nursery.../physical_properties/physical_properties.html

Science aside, my box is still watertight and going strong. The amount I have to fill it is directly proportional to the leaf load of the plants in it, and the temperature. I had to fill it almost twice a day with three big tomato plants in it! Compare that to once every week or two with a few herbs.


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## Chamfer (Sep 6, 2014)

This was a great read and nice usable build, thanks for sharing and updating.

The pine top would've been the only thing I would've warned you against, as you eventually found out.



Jon


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## Sniffles (May 26, 2015)

I made a big planter box a couple years ago and was going back and forth on building some sort of self watering system including a rain catch. Thanks for the idea. I hope you don't mind me stealing it.

Nice job!


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