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July 01, 2008


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Great idea to use polystyrene for the supports - has it been tested long enough to show that it will withstand the weight and conditions?


Greenscaper Bob

Good question Joseph. Consider this a "beta test" planter for me personally, but well tested by the Rooftop Garden Project. This 3/4" thick material is sturdy stuff. As always, I'll report progress.


I see you get up as early as I do...! I had seen this design at the RGP site but thought the material used was a hard plastic or similar. I'm going to try this with a round bucket I've been eyeing lately to transplant one of my Tomato plants which has outgrown it's pot.

Greenscaper Bob

Good out of the box thinking Joseph. This method of creating a reservoir definitely has wider applicability than just these tote boxes.

E Bone

I have really enjoyed making some homemade grow boxes, with great results in less than one month. I am already eating lettuce that I planted 24 days ago. I've also made some sub-irrigating planters for houseplants out of two liter bottles. I found all the plans online, posted by generous persons like yourself. Thanks!

One question. Where were you able to purchase polystyrene panels? I have not been able to locate any yet. I want to try that method versus using two totes for each grow box. It seems less wasteful. Also, it seems like a good way to convert traditional pots to sub-irrigated systems.

Greenscaper Bob

Nice going on making the planters!

I bought a package of Panel Foam (eps insulation board) at Lowe's. The cost was about $7 for 6 pieces (3/4" x 13 5/8" x 48") I would think that it is available at other DIY stores. Also consider using vinyl floor tiles. The objective is to have the box be easy to make without power tools.

E Bone

Thanks for the response--I'll check out Lowe's today. In terms of viral ideas, your idea to make two liter bottle planters is contagious. I am infected, that's for sure. I already gave four bottle planters to different neighbors. These neighbors are also watching my sub-irrigated grow boxes with a lot of interest. Several neighbors have agreed to collect two liter bottles for me, as well.

It seems that the only "problem" with sub-irrigation is that it forces one to confront how inefficient (and how prevalent) drench and drain watering is. I have several potted plants that must be converted to sub-irrigation because I just can't bear to see them struggle with drench and drain watering anymore, a struggle that was made obvious to me only by the thriving plants I have in sub-irrigated systems.


hello ! i find this design interesting and am planning to make some like it. have you had a chance to try it out yet ?


I grew peppers on my fire escape this past summer. All of the sub-irrigation planters worked very well including the tote box planter even though there is only a half day of sunlight on the fire escape (east facing). To see pictures, search on the word 'peppers' using the Google search box (upper left column).


thanks for letting me know that. so the design as shown is supportive enough for the weight of the wet soil ?


also, can you tell me in more detail how you made the grid and how you went about shaping the platform to shape and be flush with the inside of the container ?
on the grid, is this fitting together like a 'tongue and groove' ? i'm trying to determine how the water is able to flow under the grid.
thanks for your attention !


Would you please provide more information on how to make planters out of two liter bottles? I just can't visualize how to make them. The ideas here are wonderful, and I can't wait for growing season to begin! Thank you so much from a novice gardener.


Here'a link to another great site for reservoir containers:
I'm trying to design a system for wine barrels. I think they could be more attractive than the plastic bins.


Well, this is the one that actually inspired me to build my own self-watering planter to grow tomatoes in:

Here's my initial blog entry showing building and planting it up:
(full credit & link back here given, of course)

Since this entry, I have built a second one with the "leftover" insulation. And there's enough (from $6 worth of pink foam insulation) to build a third if I choose to!)...


I wasn't able to find the polystyrene insulation at Lowe's but this material is commonly used as a packing material. A little dumpster diving can turn up sheets of this stuff - all for free.

As a bonus, I found bags of potting soil with small rips in the bags in the trash of my local Big Lots.

I also buy my 18 gallon containers at Big Lots since they are only 5 bucks.


You're very resourceful Diane. I have a friend who buys ripped bags of potting soil from H.D. at greatly reduced prices. I'm amazed at the stuff he picks up in his truck. The stores throw it out because it costs more than it's worth to ship it back to the distributor or manufacturer.

camille lawrence

Has anyone thought: instead of the holes in the corners where soil is packed down...eventually oozing into the water reservoir chamber and over time becoming a muddy 'bout covering the chamber with a sheet of something like 14 count plastic canvas with a strip of polyester batting (capillary mat) on both sides of the platform for wicking up the water. This would keep 90% of soil OUT of the reservoir so, in long term use for large, permanent plants (ie. fruit trees, etc)it would prevent buildup of soil ooze in the sump. the Rubbermaids are not UV it possible to "paint" or "coat" each unit with something to help in this matter for longer-term use??


thanks for your easy method of buildig these containers.

I am working on several whiskey barrels,large pots and tubs for my yard using your design. I am going to try perlite for the wick as it is inert and wicks well. I just recently changed all our sprinklers to micro irrigation to reduce water consumption which is a big deal in the southwest.

thanks again, i will come back with some photos for everyone

R Brook

I love this method of growing my plants. I check with some of my local restaurants and get a number of free buckets, like pickle buckets, or the like and I spray paint then with tera cotta spray paint or other colors. I use them all over and the paint job makes them look like planters, you can even add handles, etc to make them look more like a real planter...


I got so excited after i read your blog i had to build one, no there are many. I just used polyester mat (used for roofing) for the wick. Amazing it was done in 30 minutes and ready to grow.



Heres a HOMEMADE garden that really works well.
I found this on the internet.
Its called"Earth Garden"

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