Introduction: Cost Effective Plastic-tub Wicking Beds

Picture of Cost Effective Plastic-tub Wicking Beds

Yay, finally my first instructable.

In this project, I will just go into one of my projects to create more growing space in suburbia of Aussie cities. With the ever decreasing property block sizes, subdivision etc., gardening space is diminishing, so there is a need to think outside the box.

Wicking beds aren't anything new, so I won't go into the principles of them.

Here's an excerpt from the Seed Savers Albury-Wodonga organisation (

"The concept of wicking beds is similar to the way self-watering pots work. They are built to include a reservoir of water below the soil. The ‘wicking’ part refers to the soil and plants being kept moist as the water ‘wicks’ from the reservoir into the soil. An overflow ensures that the bed doesn’t flood. Instead of watering onto the soil above the plant roots, as we usually tend to do, in a wicking bed, you instead fill the water reservoir using a dedicated inlet. When the reservoir is full, any excess water is released via an overflow.

Some advantages of wicking beds, particularly for our summers, are that they allow for constant soil moisture without becoming waterlogged. Wicking beds require less frequent ‘watering’ (refilling), so they are great for those who go away, for workplaces and just to avoid the need to water every day in summer or risk losing your plants. As the water is stored below the soil, it is possible to mulch the top of wicking beds heavily, which further helps to reduce evaporation from the soil and can help keep the soil cooler too. They do take more time, materials and effort to build, and there are some maintenance considerations for wicking beds.

As with any garden approach or tool, it’s important to ensure wicking beds are a suitable match for the type of garden and plant choices you have in mind."

Step 1: Acquire the Materials

Picture of Acquire the Materials

I found 50 litre tubs were ideal for an area at the back of my place that gets full sun.

Here's a list of the materials that I used. Most I already had from previous projects, but I'll try to at least give you an indicator or the individual cost and bulk cost.

The total cost of each tub ended up being $14.02.

Yes, there is also the cost of soil and mulch, but this will vary depending on your preference.

I use organic garden soil which is $57 / cubic metre, but I found for 7 tubs, I only needed quarter of a cube, which ends up being $2.04 per tub

For the mulch, I used Sweet Garden Organic Sugar Cane Mulch being $14.90, but per tub the cost is $0.21

So, the revised total with soil and mulch ended up being $16.27 per tub.

Step 2: Creating the Reservior

Picture of Creating the Reservior

Now you need to create the reservoir from which the soil and plants will wick the water from.

It's really easy. Just snake the drainage pipe so it's snug in the tub. I found using zip or cable ties at each end of the pipe helps keep the sock in place and prevent it from retracting.

Once you've laid the pipe, just pour the blue metal in the gaps which will help to keep the pipe in place. Just fill is to the top of the pipe and don't cover.

Step 3: Create Holes for the Re-fill and Overflow Pipes

Picture of Create Holes for the Re-fill and Overflow Pipes

On one side of the pipe, cut a hole for the re-fill pipe and on the other side, another hole for the overflow pipe. This can just be done with a pair of scissors.

You will need to drill a hole in the side of the tub where the overflow pipe will be coming out of.

The top of the re-fill pipe will sit above the soil and mulch level, so no modification to the tub required here.

Step 4: Lay the Weed Mat Over the Reservoir

Picture of Lay the Weed Mat Over the Reservoir

Finally cut the weed mat to size.

It doesn't have to be perfect, but do your best to cover up as much of the reservoir to prevent your soil falling into it.

Step 5: You Won't Be Able to Stop at One

Picture of You Won't Be Able to Stop at One

So that's it.

I ended up making 7 in total and planted things such as chillis, tomatoes, strawberries, lettuce, zucchini, spring onions, get the idea.

I'm still in the process of researching what else I can plant, but my aim is to use these for plants with a shallow root base so as to not use up precious real estate in my larger, deeper garden bed which I can use for plants which require deeper roots.

Enjoy and let me know if you end up creating your own.

Step 6: Update to the Plastic-tub Garden

Picture of Update to the Plastic-tub Garden

So, this addition was always in the pipeline, but with a particularly warm day wilting a few lettuce seedlings, I brought it up the timeline.

I purchased some garden stakes to create a bit of a skeleton structure around and over the beds. Once that was completed, I just measured and cut shade-cloth to size and then just zip-tied it to the structure. As you can see in the photo, I can have the shade-cloth covering both the top and front side, or roll it up and just have it on the top.

Hopefully this will not only reduce the suns rays wilting any plants, but prolong the life of the plastic tubs from the UV rays...many thanks to all who have already made comments and constructive criticism regarding UV vs plastic.


DIY Hacks and How Tos (author)2017-10-28

How well does the plastic hold up against UV. I tried planting in small plastic storage tubs earlier this season and the plastic turned very brittle and started falling apart after a few months.

I'll let ya know after the Spring/Summer season goes...the consensus throughout earlier comments is that this is bound to happen...just a matter of seeing how long it takes

puttycake (author)2017-10-24

Hi...I see that folks are commenting about substituting the plastic bins for pallets. I'm posting this link regarding how to determine if a pallet is safe to use for projects.

Thanks for the link...will definitely have to have a read of it.

The main purpose of using the pallet wood is that it should be readily accesible and most of the time free.

Once you'd build a garden box out of it, you'd still line it with thick black pond lining so you can still have the reservoir of water at the bottom.

Hope this helps.

IvliaB (author)2017-10-24

A fabulous idea, and one I will seriously think about. One way to protect against the uv light would be to paint or otherwise cover the sides of the plastic tubs but checking costings you might find it cheaper to just replace the tubs when needed. If you are serious about growing more food items check out the book 'Square foot gardening', there is a website which will explain the principles. I got a copy from the library and photocopied the relevant pages. I have been able to keep a family of 4 adults supplied with minimal water usage although the wicking would help there. Well worth a look, can easily be modified to suit different needs but can grow deeper rooted items like carrots etc. as well in tubs and the like. Not a problem in Australia I know but a word of warning for those in other climes, a wet summer (and we've had a run of those lately here in Ireland, family in NZ say the same there too, although they say it saves on the irrigation) and the vegetables will rot in the ground. The last few years I've lost everything, even with lots of holes to allow the water to escape. Will try your idea though and add a plexiglass roof over them, I'd rather irrigate than risk the flooding which I've suffered recently. Many thanks, I'd never though of using these boxes before but it makes perfect sense.

JohnC430 (author)2017-10-21

i dont understand the purpose of the weed mats below the soil. is it just to separate the soil from the gravel? if so then some of those cotton hand towels that are sold in bulk would be cheaper to use. i checked the prices of weed mats and they are very expensive.

Sure you could use any porous material. I don't know which weed mat you may have seen. I've included the costing of what I bought and I think it's pretty cheap. Regardless, the whole purpose of the barrier is to ensure the soil (organic material) doesn't sit in water and develop bad smells and other stuff...I'm not big on the sciency stuff, but everywhere else I've see wicking beds, there's been some sort of a barrier. Hope this helps.

The barrier also keeps the roots of plants from dropping into the wet zone those allowing too much moisture uptake. It also makes for easier clean up when you get too much moss or other material on rocks or want to replace the soil - not things you would do often but making them easier to do when the time comes.

Thanks heaps for the input and encouragement.


Cueball21 (author)2017-10-23

Great job for a first 'ible!'

Thanks for sharing the step by step instructions and costs.

Soose (author)2017-10-20

Great Instructable. Well done, like your photos and descriptions. Making the shade cloths would be a good topic for another Instructable. Including cost?

dewey302 (author)2017-10-19

For those concerned about the impact of UV rays on plastic you might try wrapping the tubs with weed barrier cloth (like what is used in this instructable to cover the rocks.) I've had good luck here in the Central Valley of California (read VERY intense sunlight) by shielding my plastic pots this way. It also helps prevent over heating of the root systems of the plants. Unfortunately, weed barrier is not the prettiest material and it can be a challenge fitting it around odd shaped containers...but it is functional. I've had plastic pots in the direct sun for five years or more with no obvious deterioration.

Many thanks for your comments. V2.0 should hopefully be made out of reclaimed wooden pallets so I don't have to worry about that darn UV. But, if I muster up the motivation, I may cover it with the weed mat to prolong the life as much as possible. My belief is anyone who truly enjoys the gardening and the rewards of the fruits of their labour, isn't that concerned about the appearance but the final result. But that could be my lack of finance and time to invest in something prettier :-)

FergusK made it! (author)dewey3022017-10-19

Yes, good idea. Other options are to:
-use UV resistant planters (more expensive and difficult to find in large sizes)
-make your own out of concrete
-use terracotta planters, block the drainage holes with epoxy, drill overflow hole.

Terracotta is the version I'm using now. I don't use gravel, but make a reservoir at the bottom by using old pallets to make a frame, and use old cotton t-shirts as a wicking material.

In the photos you can see, a circular terracotta pot in process, as well as a completed rectangular terracotta pot and some older UV proof plastic pots. All with the same sub-irrigation system.

Many thanks for your comments. Yes, the breakdown of the plastic is a definite theme in the comments, but I'm taking it as constructive criticism for future versions. I was a bit late to the planting party in spring, so rather than building something a bit more hardy, I just opted for something readily available.

V2.0 I think I'll try to create out of reclaimed wooden pallets.

EmmitS (author)dewey3022017-10-19

A more expensive, but more attractive alternative would be to make a wooden box and set the planter down into it. The problem with plastic outdoors is ultra violet light Which breaks down the plastic and makes it brittle. shield the plastic from uv rays and the plastic will last much longer.

LorantS1 (author)2017-10-19

Great instructable allencvetanovic. I had been thinking about doing one in a cut down ICB cube but this approach is better and more flexible for the average garden. I had a chuckle at your reference to "blue metal" and wondered how that might be interpreted by our friends in the Northern Hemisphere but your pictures made that very clear regardless.

Many thanks for your comments. Yeah the ICB cube would be awesome. Unfortunately that kind of space eludes me. I think I did see another instructable that has done that. My one comment about that though would be the width and depth of the cube. I've read many literature that talks about making garden beds easy to access by limiting the width of them to a metre. That way to have half a metre from each side to access into the middle of the garden bed. I hope that made sense. I just struggle to see how one would access the middle of the cube if it's as large as I imagine it to be. Let me know how you go if you do create it.

Oh, I have no idea what "blue metal" could be interpreted to. A fusion of blues and metal music? Or maybe a drug?

FergusK (author)2017-10-19

As others have said, you are going to have problems with those plastic bins. I did exactly the same thing, and they died within a year or so. You may also have problems with the plastics leaching out horrible chemicals into your plants. Not a huge issue if they are not edible.. but if they are.

I've now replaced all my plastic planters with ceramic and wood ones (the only plastic I've used is the water pipe). But you've inspired me, I'll add an instructable!

Many thanks for your comments. The breakdown of the plastic was something that didn't even cross my mind, but I suppose these kinds of platforms help to get constructive criticism from others so that future versions can address any issues. I think my next ones will probably be made out of reclaimed pallets.

kmpres (author)2017-10-19

Very nicely written and congrats on your first instructable! I never heard of wicking beds until now but that's not surprising considering my black-thumbed total ignorance of gardening generally. I do, however, have some experience with plastic. Just be aware that your plastic tubs may not last more than a year or two before they'll shatter into tiny pieces. The sun's UV radiation tends to break down the chemical structure of inexpensive plastic items turning them eventually into brittle flakes.

AussieUrbanFarmer (author)kmpres2017-10-20

Many thanks for for your comments. Yeah, the resounding theme in the comments seem to be the breakdown of the plastic tubs in direct sunlight. V2.0 should hopefully be something a bit more hardy. Thanks again.

Thunderhawks (author)2017-10-19

Maybe too soon to ask:
Do you have an issue with the plastic bins deteriorating/breaking as the sun dries them out? My first testing attempt at growing tomatoes resulted in a broken bin after a lot of sun exposure.

Yeah, I'm sure I'm going to have this problem. The breakdown of the plastic was something I just didn't consider. Version 2.0 should hopefully use something maybe UV treated or I might recycle some pallets to create wooden beds. Thanks for the comments.

therewillbeblood (author)2017-10-19

So what does the actual wicking, meaning what draws the water out of the reservoir and up into the soil above it? I see you have a sock and the mat, but how does that assist in drawing the water up? Most wicking bed plans I've seen have actual wicks that enter into the reservoir via small holes on top and then are embedded into the soil.

I'll be honest that I haven't seen the kind of beds your referring to, but I'd be happy if you sent me a link so I could check it out.

In regards to wicking, the soil wicks the water through something called capillary action. Capillary action is the same effect that causes porous materials, such as sponges, to soak up liquids. Capillarity is the primary force that enables the soil to retain water, as well as to regulate its movement. Hope this helps.

afcondon (author)2017-10-19

Nice project.
You might find that the plastic tubs get brittle in the sun - it's happened to me with tubs like those - you can probably extend their life a bit by covering them somehow or ensuring that only plants and soil get direct sun.

Many thanks. Yeah...the breakdown of the plastic tubs in the sun was somethings I didn't consider. But, as with most things, you create, you learn, and then make it better the next time round. Thanks for the constructive criticism.

Swansong (author)2017-10-13

Great first instructable! I want to see what your plants look like once they've been growing for a while. :) I wish it was warm enough for us to have a setup like this where we live.

Will do and thanks. I'll post an update photo when they get bigger.

I think these would work great if you set up a mini greenhouse. That way you could at least prop up the temperature a bit and maybe get an early start on the growing season.

All the best.

About This Instructable



More by AussieUrbanFarmer:Apple-smoked Homemade PancettaCost Effective Plastic-tub Wicking Beds
Add instructable to: