DIY Self Watering Planter Box

This is an almost free self watering planter box anyone can build themselves, and it will barely cost you anything, and it will take you about 30 – 60 mins depending on how slow you are at doing things. I got the inspiration from a Brisbane man who appeared on the ABC’s Gardening Australia program.

The Brisbane man had created these self watering boxes which i just had to try to recreate, and create a blueprint for.  They are portable, highly effective, almost free, and require barely any space, easy to make and will provide you with plenty of vegetables or herbs without having to water daily. To watch the episode, click here.

DIY Self Watering Planter Box

What do you need?

You will need the following items to build this self watering planter box:

  • A foam box without holes + the lid (you can get these from your local greengrocer or seafood shop, and they will just give them to you).
  • A PVC pipe (ready to cut to size)
  • A saw or cutting implement to cut the PVC pipe
  • A pair of scissors and a Stanley knife
  • Waterproof tape
  • Stick (free from your garden)

How do i make it?

Firstly get your foam box. You can get these foam boxes from any green grocer, supermarket or seafood / poultry shops. Be brave and ask (you don’t get if you don’t ask) and most places will be glad to get them off their hands and give them to you, and no one will want any money for them. If they want money or make it an issue, move on and get them somewhere else. In 1 day i was able to get about 5 from a supermarket down the road, all free.

Foam Box

Get the lid and cut around the inside lid following the groove using a stanley knife. This is the best implement to use when cutting into the foam.

Cutting the lid

Once you have finished cutting out your divider from the lid, it should look like this.


Next you want to measure the PVC pipe ready to cut to size against the foam box. This will be used for adding water when needed, and to house the float which will tell you when you need to add water to the box.

Measuring the watering pipe

Once you have measured the pipe, cut it down to size, as shown below. It should be the size of the foam box itself.

Watering Pipe

Next what you want to do is cut 3 pieces of the PVC pipe, 2 as supports to hold the foam divider in place (it’s up to you on the length you want to cut, remembering that water will only go as high as the PVC pipe length you cut. The third piece needs to be slightly taller than the other two as it will be used as the wicking pot. Cover it with netting using anything to secure the netting in place.

A wicking pot acts like a candle but upside down, and with water instead of fire. Confused? Basically a wicking pot is used to draw water up into a garden bed from a water source below. This allows the plants to draw water when they need it provided there is enough water in the reservoir from where the wicking pot is drawing the water from.

PVC piping

To allow the wicking pot to work, you’ll need to cut a hole in the divider so the wicking pot will fit in it. Simply just cut out a hole using the PVC piping as a guide and with a stanley knife.

Cutting the hole for the wicking pot

Once you have finished, it will look like this.

divider with wicking pot hole

Insert the wicking pot into the divider so it looks like this.

divider with wicking pot

So now you need to cut a hole in the divider for the water pipe so it can be inserted into the planter box. Use the PVC pipe as a guide and cut around it with a Stanley knife.

Divider with water pipe

Congratulations, you’ve now completed the majority of the work, and it’s really more about assembling and the finishing touches. So to get ready to assemble your planter box, place the two support PVC pipes in the bottom of the foam planter box, and the water pipe as shown below.

Ready to assemble

Ok here’s the satisfying bit, when you finish assembling the planter box by adding the divider, and you realise you have just created something awesome that’s going to give you some great produce without having to water it all the time, and it’s barely cost you anything to make.


So now you’ll want to add your overflow hole which will allow water to overflow out of the planter box, and not fill up higher than the divider and drown your plants. Determine where your overflow hole should go which should be just under the foam divider, and use scissors to carve out a decent sized hole for the water to overflow out of.

overflow hole

Cool, that’s pretty much it. Now, before you do anything else, determine where you are wanting to put the planter box and put it there before you start adding in soil and water. It can be difficult to move when full of soil and water without a trolley.


Now to add in the dirt and start prepping to add in your seedlings. You should start with filling the wicking pot with soil so the water has something to get sucked up with, and then cover the rest of the of the divider with soil.

first soil

Add in as much soil as required. I think the foam divider can handle any amount of soil without breaking or caving in.

Finished soil

Now get your seedlings ready so you can plant them in your planter box. I’ve chosen Rhubarb seedlings that i’ve grown from seeds in my awesome greenhouse. Can’t wait for Rhubarb crumble!


Once you’ve added your seedlings, you may want to mulch. I like to mulch, i think it has to do with conserving water, and keeping the soil moist. I think you’re also meant to water the soil before adding mulch, but i’m not sure. I’ll leave that to you to research.


So once finished, your planter box should look reasonably similar to the planter box shown below.

DIY Self Watering Planter Box

Ok, a self watering planter box requires you to add water to it, unfortunately it’s not automatically replenishing, so add your water by adding the water through the water pipe.


You’ll know when you’ve added enough water when it starts dribbling out of your overflow hole.

So how will you know when you need to add water to your self watering planter box? Simples, create yourself a float using some of the foam scraps, and a stick from in your yard.


So put your float in the water pipe so it can float on the water, and you can use the stick as a gauge to whether the planter box needs water or not. You will have to remove the float when you add water to it otherwise you may break your float.

OK, so this step should really have been completed when the planter box is empty. You’ll need to mark the stick at the point that shows the float being at the bottom of the planter box (showing that the planter box is empty and needs water). this can be marked by using colored tape.

marking the float

Now when you see the tape level with the top of the PVC pipe, you’ll know you need to top up the planter box with water. Simples!

And that’s that, you’ve created yourself a self watering planter box that will tell you when you need to add water, and it barely cost you a thing, and you’ll barely have to water your plants, you lazy stingy bastard you. No seriously though, congratulations, you’ve recycled, and saved yourself a decent amount of money, and you’ll have a bumper crop to show for your efforts, well hopefully anyway.

DIY Self Watering Planter Box

Hope this helps, and please share with your friends, don’t get duped into spending lots of money for something that’s ridiculously easy to make and is helping the planet by recycling.

Your helpful gardener.

19 thoughts on “DIY Self Watering Planter Box

  1. I’ve been doing some research on planters, and had a quick question: what is the benefit, generally, of having a bottom on the planter? If you were going to place the planters in a permanent location in the yard, could you not just have walls to hold the soil with no bottom? That would be very easy to build with a few pieces of wood.

    • Yep Mac i agree. you don’t really need a bottom to the planter. I choose to do this so i can move them around to get the benefit of the sun as it moves across my yard.

  2. HI,
    is the netting that you use on the Wick anything special? I have used flyscreen but am not sure it will draw the water up to the soil.

    • I think the netting isn’t an issue, it’s more about the fact that you fill the wick with dirt, and that’s what acts as a conduit to draw water up from the water reserves.

      Hope that helps

  3. Aloha… Wasabeface… Love your presentation best on the internet. Been using these boxes for a while. I just love em. I do mine a little different. I use 2 liter soda bottles. Cut the top of one ,the bottom of three and a uncut one at the end. I join them all to form a tube. Two rows of that. The third row I use 16 oz bottles three to four inches shorter on both sides to the 2 liter tubes. These are for the potting mix to wick up through. I use a soldering iron to put holes in the tubes so that the plants can breath. They seem to grow faster. From the top in the corner I cut an x in the 2liter tube, cut the bottom of a 16 oz bottle fit the neck through the x for the fill tube. The side of the 2liter bottle I cut another x fit in straw for the over fill. Cut a hole in the side of the box for the straw and were done. Fill with a good potting mix. Find a nylon stocking fill it with a 10-10-10 ferdalizer. Dig a little trench stretch the sock, cover with mix. As for the cover I use it for my 6 pack starters. Today is Easter Sunday. PEACE to one and ALL. Mahalo for sharing.

    • Hey Pomai, thanks for the kind words and comment. I’d love to see a pic of some of yours so i can compare. I love the nylon stocking idea with fertiliser. I will have to try this.

    • Hey pomai, Thanks for sharing and I like the sound of yours as well. I have the parts you mention, but I still dont understand how the 16oz bottle wicks work with your method. How do they make a connection with the water? Sorry for the dumb question:( A picture or hand drawn diagram would be really helpful if have the time. If not, thank for sharing your idea, its sounds great! God Bless

      • Aloha debby
        Where I come from. They say the only dumb question is the one that no body asked. So let’s see.
        Up above, there is a picture of the inner shelf with the wicking stem in the center.
        In my version, I have 2 tubes of 2liter pop bottles side by side there isn’t room for a third 2liter tube so I used 16 oz a and w rootbeer pop bottle 8 inches shorter than the 2liter bottles. I have the same size box as above. So, when I lay down the 16 oz tube it’s 8 inch’s shorter. So I center it,leaving a 4 inch space in both corners. This 4 inch space becomes my wicking stems. In the another corner I cut an x in the 2liter tube, get a 16oz bottle cut the bottom half inch out with the other end the neck get it thru the x. This becomes the fill tube.
        To make a tube- 1 full bottle, cut the bottom of the next 3 or 4 join together, to càp the end cut the top and use the bottom. Put tube in box to adjust the size. Use solderig iron to make holes in tube.
        Hope this helps

        A hui hou

    • Aloha wasabiface
      What a great surprise to come across your blog again:-) 🙂 🙂 . Just so happen to type in styroform box garden. Like a rare shell on a beach, our paths cross a again.
      Hope every thing is growing well for you.
      Sorry still haven’t figure out how to get those pics up. But I’m glad to see your aloha for things we share.
      Styroform box gardens
      Love your up dated version. But, if it was me. I would have at least 2 wicking holes,lots of holes on the inner shelf. Between the water level and the inner shelf is an air pocket. Plants like to breath through their root system. That’s what make them grow faster. Love the float idea.
      I’m starting to jones out. Need to go out side to check on my babies.
      A hui hou ( till the next time)
      Keep the aloha growing

  4. Innovative, loved the presentation. Been using Planter boxes from Purna Organics since 2 years and have great experience they are just awesome, suggesting you to look into it.

  5. Hi, I saw the Gardening Aust. presentation and the light went on. Derr…why didn’t I think of that. Finally got boxes and was checking on instructions and saw this site. Ahhh that’s even better, and my sons a plumber, so always bits and pieces of pvc pipe. I didn’t put stocking or netting over my wick, I got out the grinder (a hack saw will do) and put 4 x 1.5iinch slits up the sides of the wick pipe and it draws the water up perfectly. Had a bumper crop of cucumbers, tomatoes and capsicium. Just got my hands on a few more boxes and the skies the limit. Happy Gardening everyone.

  6. Hi,
    We are so pleased you taken our Invention: Selfwatering planter box and share it with others.
    There is more our ideas and inventions to share on our website.

    • Hi thanks Roman

      When i saw your episode on Gardening Australia, i was very inspired and just amazed and what you had managed to achieve, especially in a rental, and with minimal cost. All it takes is a little effort and a can do attitude to create some amazing things.

      Because of you i’m very much inspired, and there’s no excuses anymore, just how can i do this, and think of ways to become more self sufficient.

      BTW – link to your website for others visiting the site:

      Thank you for coming by

  7. Hello, I would like to start off by saying this information provided really is helpful (and for some reason, I have two foam box lying around the house). Just recently started gardening and I’m looking at ways to start some growth!

    Was looking through the steps and I have a few question:

    1. The support for the divider, are they just placed in the foam box itself? Or are they glued/stuck through the bottom of the foam box?

    2. You mentioned that the wicking pot’s pipe need to be longer, does it have to be flush with the bottom of the foam box or do I leave a gap between the bottom of the PVC pipe (with the netting) to allow water to be sucked up? And should the top of the PVC pipe be flush with the divider or protruding out a bit?

    Thanks in advance for the help. Really am new to this. =]

    • Hi Daniel and thanks for popping by.

      1. The support for the divider is purely just some more PVC piping cut to size. This holds up the divider. I don’t glue them or anything, and they seem to stick ok. Haven’t had any problems so far.
      2. I made the wicking pipe just sit above the bottom of the foam box to allow the water to be sucked up. It can protrude out a bit as it’s covered in soil and still works the same.

      Good luck with it and keep us posted.

      • Thank you for the reply! Will be doing it tomorrow. And I’ll share the end results then~

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