Concrete in the Kitchen Garden

I think the use of concrete in the kitchen garden is something that should be considered more often. Concrete is not pretty but since the main purpose of the kitchen garden is to produce edibles the benefits of concrete as a building material should be kept in mind.

The guy who started this garden I have now, back in the 1950s, was certainly very fond of concrete. In my post about soil improvement I mentioned the large 3 x 3 m (10 x 10 ft) concrete bed I found, I’ve talked about the concrete compost tube too, that I think he built too.

I also found an old concrete roller, that was probably used as a lawn-roller, but left behind in an old shed in the back of the garden.

What’s interesting is the age of the concrete roller – it says “1957” on the side of it! Written with a finger in the wet concrete. Now imagine a normal raised bed, perhaps waist high, made from this stuff, lasting 50 years! No need to worry about what type of wood to use, or count your money to make sure you have enough to buy the lasting type.

Concrete can also be used for aisles, as the perfect weed stopper between beds. A more flexible solution would be to pour your own concrete slabs that can be moved around, to be able to modify size and shape of each bed.

Lynn Mentgen-Gillespie talks about using store-bought concrete blocks, namely cinder blocks, in her ebook Cinder Block Gardens.

Be prepared to do some heavy work if you choose to use concrete in your kitchen garden, but at the same time enjoy the benefits of custom made tools and structures, that will last a lifetime.

Soil Improvement

I have really got my hands full with this new garden. It is both awesome and scary at the same time, because I get so many great ideas I want to try out, but the plot is still a wilderness after two months mid-season. I wonder if I’ll ever be able to handle this beast and make it into a neat, food-producing kitchen garden. It’s the perfect way to exercise patience and faith – the carrot seeds took an awful long time to grow into seedlings, and the soil needs nutrients really bad. I’m not sure if soil is the right word. It looks like something you’ll find at the seashore, so I’ll have to have faith in the yearlong composting process, and that I’ll be able to turn my kitchen waste and ornamental garden waste into humus for the vegetable beds.

I’m figuring out a plan for the placement of each bed, and digging away. I discovered what I thought was a discarded concrete building block, but it turned out to be a large 3 x 3 m concrete bed that had been buried in garden waste for many, many years, judging by the height of the pile on top of it (about 1.5 m). Now I just need to find out if it’s some kind of pool (i.e. call in the ducks), or an ordinary bed without a concrete floor in it (i.e. reread the Food4Wealth ebook and use it as a Food4Wealth bed).

No matter what – the potatoes I did manage to plant in the ridiculously sandy soil will soon be ready for harvest, and I’ll appreciate every small bite.

Kitchen Garden Plot Tour 2012

Maybe I put a bit too much energy into this – I wanted more space for my kitchen garden (in fact, I had almost no space at all) and now I have a park on my hands! Well, most of the garden is ornamental, but it still takes time for me to mow the lawn and trim the bushes and hedges. But it’s awesome, I love it!

It took some time to get used to the snakes crawling around in the tall grass, but they’re pretty harmless. These videos below were shot a couple of months ago and now that the grass has been mowed several times I think the snakes left.

The ornamental garden and the kitchen garden are connected through a beautiful old wooden trellis, but the kitchen garden was still a complete wilderness when the videos were shot. It’s okay, I like the challenge!

Half of trees in the far back of the garden are cherry trees, and they’re very tall, maybe 8 meters or so. It’s actually raining cherries down there if you get the timing right.
A couple of big piles of sticks have been left to rot, with God knows what kind of creepy critters living in there (among snakes, yes).

I’m looking forward to harvesting Victoria plums and apples from tall trees planted long time ago in the kitchen garden.

And oh, check out the custom made concrete composting tube, and the concrete drum (whatever that has been used for?) It looks like the garden and the tools and stuff were left behind in a hurry and haven’t been touched since – just like an old town from the gold rush…

The far end has been fenced off against deer, with a tall fence, with a view to the golf course next door; “Clock!” And duck. 😉

New Kitchen Garden in 2012

I moved into another house a couple of months ago, and with that came a new garden for me to build. It was a complete unattended wilderness when I moved in but after much sweating it’s beginning to look like a kitchen garden.

This picture was taken about 6 weeks ago when I prepared a bed for potatoes:

It’s not good to start from scratch in the middle of the season with a wilderness, but at least a fun challenge. I’ll probably end up with a lot of garlic this season, as they’ll go in late, as far as I remember. It’s pretty chaotic down there in the kitchen garden at the moment as the race to get at least something growing is on before the season ends. Of course there are always crops like lettuce, spinach and radish that will produce something fast, but it’s not until next year I’ll get a normal yield from the garden.

The potatoes are growing well and will soon be ready for harvest. As I realized how late I was in the season I started digging like a madman, even in the pouring rain, but with an unexpected positive outcome: The soil is much easier to work with when it’s wet!

That is probably only true right here where the soil is very sandy, in fact too sandy, but for me it has always been the other way around: When the sun was shining, I was out there digging, which meant that the soil was dry, sometimes as hard as rock. If you have to go through a layer of grass or lawn it is worth to make a comparison of the soil consistency after a period of rain versus a period of sunny weather. I’m impressed with the speed at which I could go through a complete bed like the above one, but the soil might also be heavier to lift, especially if you have clay soil I guess.

In order to improve the sandy, lifeless soil here I’ve setup a primitive composting box made from wire mesh and round poles. There’s already a very cool looking compositing concrete tube installed in one corner of the garden, that I’ll be using as part of a 3 year system, where I’ll be moving the material from the Year 1 box to the Year 2 box, until the composted material ends up in the final Year 3 box, or tube, before it’s completely composted and ready to be spread out on the beds. (Thanks to Peder for this idea!) In the process of moving the material from box to box the material will be turned and mixed, so that green parts will meet with new brown parts and the composting process will be optimized. If the missus gets her rabbits installed at the other end of the property I’ll have access to manure that will speed up the composting process tremendously and I might be able to cut of a few year of the process. We are already collecting kitchen waste and throwing it into the compost to speed up the process so the lifeless sandy soil is soon a thing of the past.

Raised Bed Designs – Part 2

It’s time for another round of raised bed designs here in 2012, where raised bed gardening seems to be as popular as ever. The benefits of using raised beds are (according to Wikipedia):

  • Higher yield
  • Creates a micro-climate in which weed growth is suppressed
  • Moisture is conserved
  • Extends the growing season
  • Plants grow easier due to loose soil
  • Easy on your back due to tall building height

Below you’ll find examples of raised bed designs:

A circular raised bed made from round pressure-treated wooden poles:

Circular Bed
Photo by Karen Blakeman. (Barracks Lane Community Garden, Oxford, England, GB).

I think rounds beds are definitely the most beautiful, but also least efficient when it comes to yield, because you waste grow space in the ‘corners that are not there’, compared to rectangular beds.

There may be a health issue when using pressure-treated wood – take a look at this post for more info: Raised Garden Bed Plans

If the poles have the same length below ground as above ground they are be able to support themselves, held in place by the weight and pressure from the soil.

The next two photos show lots of ordinary raised beds but they are special because they are built on the property of an elementary school:

Classroom Plots
Photo by Billie Greenwood. (Casa Alegre, Santa Fe, NM, US).

Elementary Classroom Raised Beds
Photo by Billie Greenwood. (Casa Alegre, Santa Fe, NM, US).

I haven’t seen anything like that in my country, and certainly not a kitchen garden of this size (although I’m wondering what the grass like plants are, but I’m pretty sure I see lettuce in one of the beds).

Working with raised beds in school is a great way to teach kids about food and energy, and certainly an improvement from my time in school, where the teaching was limited to cress growing in a windowsill 😉

I’m not sure if the next one qualifies as a raised bed:

Finished Garden
Photo by R Berteig. (Monrovista, Monrovia, CA, US).

I guess it depends on whether you took the few steps down into the middle or you’re standing on the normal ground level.

I’ve seen this type of bed used beneath a greenhouse, where the greenhouse is placed on top of the outer wall, although this was in a smaller scale. It probably has to do with the building height of a greenhouse, to be able to get more headroom when working inside, so you lower the “floor”.

Raised beds made out of concrete and stone will last a lifetime, so make sure you get the design right the first time, or be prepared to bring in the heavy machines to clean up any mistakes.

This is the basic raised bed as mentioned by John Seymour in his book about self-sufficiency:

Cameroon Nursery Shade, Raised Bed
Photo by Trees For The Future. (Cameroon).

On average your soil should be warmer since it’s raised above ground (although cold soil shouldn’t be a problem in Cameroon…)

While taking care not to walk on the raised bed soil the members of the Njimacob farming group are building a support to create shade against the burning sun (about 1,000 km / 620 miles from the equator).

The planks in these raised beds look like they are made out of expensive, long lasting wood, because of the dark color:

Raised Bed Designs
Photo by Poppet with a Camera.

A more dark type of wood is probably going to last longer that a light colored type. If it has been treated with oil for preservation it will also be darker, and last longer.

If you want low maintenance aisles between your raised beds you can lay out sheets of plastic for weed suppression between the beds as show in the picture above. I find an aisle width of 50 cm / 20 inches to be sufficient.

I like how tall this next one is:

Raised Bed Designs
Photo by Mike McCune.

This is actually the minimum height every raised bed should have in order to be easy accessible. The challenge is to find enough extra soil to be able to fill it up, but you’ll get fantastic root crops with this height. You can also place a raised bed with this much soil in it on a hard surface like concrete tiles, since the plants already got the room they need and don’t need to dig further into the ground.

The above one looks like it has been painted which will make it last longer. Just make sure the paint is environmentally friendly.

You don’t even need mortar to build a raised bed from stones, if you use strip stones that fit together very well:

Browning Residence, Raised Bed
Photo by Jay@MorphoLA.

This is one of the most robust raised beds I’ve seen – made of bricks and mortar which means it will last a lifetime – or four:

Backyard Raised Bed Designs
Photo by Choking Sun.

It has a good height too, but the only problem is the width, at least for kitchen gardening – it’s impossible to reach the weeds popping up in the middle of the bed without crawling into it and compressing the soil and getting dirty knees, feet and palms. I prefer a raised bed with a maximum width of 1 meter ~ 3.3 ft.

This particular raised bed was most likely built as an ornamental bed for flowers etc., and it matches the house well.

Backyard Raised Bed Designs
Photo by Choking Sun.

A nice looking right-angled raised bed made out of planed timber:

Farm Soil Amendments, Raised Bed
Photo by Milton Taam.

Ordinary raised beds, but with a tall fence around them to keep out animals – or kids 😉 Toddlers don’t know the difference between weeds and vegetables, so if you’re serious about kitchen gardening you might want to consider setting up a fence around the “other babies” (= precious homegrown vegetables 😉 ). This will save you a lot of stress.

Notice the border between the raised bed in the middle and the lawn – the grass grows taller here because the lawnmower is not able to cut that close to the planks:

Fenced Raised Bed
Photo by Amanda B.

You’ll need either a grass trimmer to remove this last line of grass, a pair of scissors and a lot of patience, or perhaps a line of paving stones around the beds, if you don’t want this perfect habitat for slugs right next to your lettuce.

A beautiful garden with a mixture brick and mortar and wooden raised beds:

Bricks, Raised Bed Designs
Photo by PermaCultured. (Newtown Community Garden, corner of Longdown & Stephen St, Newtown Sydney)

A collection of different types of raised bed designs to get ideas from, and perhaps you already know how you want to build yours? Project photos with comments are welcome – please send them in and we’ll do a showcase post here on Contact details are here: Contact

Six Reasons to Harvest Rainwater

This is a guest post written by Amy Lizee from

Rainwater harvesting is not something that is new to society. In fact, “the oldest evidence of roof catchment systems date back to Roman times. Roman villas and even whole cities were designed to take advantage of rainwater as the principal water source for drinking and domestic purposes since at least 2000 B.Cs” 1

However, as society developed and evolved, the use of rainwater become less and less. Although individuals in the agricultural segment use rainwater to grow their crops and feed livestock, it has been almost completely forgotten in the urban setting.

While rainwater harvesting can be a complex process with high-tech systems, it can also be a simple barrel with a secure lid. Regardless of which form of catchments you choose to use, switching to rainwater provides many benefits to yourself and the environment.

6. Provides a healthier source of water

Rainwater is a naturally pure source of liquid. As it has not gone through any municipal treatment centers or filters, it remains free of chlorine, pesticides and dissolved minerals. This makes it a very good option especially for individuals on low sodium diets or any one with weak immune systems.

5. Water conservation and reducing water demand

Individuals who use harvested water are playing a part in water conservation, which is one of the most important environmental concerns of today. Although the majority of the Earths surface is covered in water, only 2.5% is fresh water and fit for consumption. Of this, “1.6% of the earth’s fresh water is trapped in glaciers and polar ice, which leaves less than 1% in our lakes, rivers and streams for human consumption”. 2

By harvesting rainwater, you are using less municipal water and thereby, reducing your urban consumption. In turn, you are also reducing water demand by removing one home or part of a home from the urban water plate.

4. Supplement municipal water in time of low availability

Linking to the first point, in times of drought or low water supply, homes that harvest rainwater are able to supplement their regular water source during droughts and low availability or even during storms and power outages.

3. Can be used to divert rainwater to toilet flushing or other functions

Not all homes harvest rainwater for the purpose of drinking and bathing, but luckily there are many other areas in which rainwater can be a useful supplement for municipal water sources. For example, rainwater can be harvested and used for lawns or gardens, agricultural fields as well as flushing toilets or doing laundry. Many people don’t realize how much water these daily activities can take up. In fact, “landscaping, laundry and flushing toilets account for up to 75% or more of fresh water used in the average home”. 3 By switching some of your regular activities to rainwater, you will reduce your urban consumption as well as your carbon footprint.

2. Reduce storm drainage loads

This is perhaps the single most important environmental effect of harvesting rainwater. Since a storm drain lacks a filter, untreated storm water often finds itself in varies bodies of water. This has a huge impact on our environment because some of the most common storm drain pollutants included: motor oil and fuel, litter, paint and paint thinners, household cleaners and fertilizers. All of these pollutants affect wildlife and many of them do not breakdown naturally. So, by reducing storm drainage loads, pollution is declined, thereby reducing the impact to our natural plants, wildlife, rivers, streams and oceans.

1. Save money

The usage of water in your home requires energy, which we pay for. When you reduce the usage of urban water in and around your home, you are also reducing the energy costs associated. In some cases, this means a 35-40% savings on your annual household water bill! If the environmental and health benefits didn’t get you, I am sure this one will!

“All the water that will ever be is, right now.” – National Geographic, October 1993

Now that you are aware of the benefits to rainwater harvesting, I am sure it seems like a much more colorful option then it did before. While switching over might seem like a big change, the benefits far outweigh any negative impact.

There are hundreds of ways that we can save the environment each and every day, but all of them require change in the way we do things and the way we view the world around us. By taking what Mother Nature has given and using it in its most natural form, we are connecting to nature and protecting it for future generations. is an interactive website for individuals to come and discuss the environment from green business to natural disasters. We feel it is important for people to come together and share their thoughts, ideas and visions for the future. The more we can communicate what is happening in our world, the more people can be educated and the more we can progress. Beyond you can find us on Facebook and Twitter where we are continuing to spread the message about our global environment and the impact that we have on it every day.


Are Your Tomato Plant Leaves Showing These Symptoms?

Photo by jayneandd.
We all want great tomatoes from our tomato plants, but often the plants are hit by diseases or pests and although some fruit develops wouldn’t it be nice to maximize the yield from each plant to get a killer crop, by curing the diseases or getting rid of the pests?

The first thing to do when you notice a not so healthy looking plant is to find out exactly what is going on, so that you can begin you search for the cure. Below is a list of symptoms together with possible causes to get you going on your quest to grow the best possible tomatoes. Try doing a Google image search once you get an idea of what your tomato plants are trying to tell you, and see if it looks like what you’re seeing on your own tomato plant leaves.

Discolored leaves


As you can see below, a yellow coloring of your tomato plant leaves can be caused by many different things. The color yellow either covers the entire leaf, is limited to patches or limited to just spots, depending on the cause:

  • A lack of nitrogen affects the lower leaves. It spreads to the upper leaves.
  • A lack of calcium affects the upper leaves
  • A lack of manganese is rare, but will result in dead patches on the leaves, ringed in yellow
  • Wilt diseases can cause a shortage of nutrients, which will then result in a discoloring of leaves
  • Fusarium Wilt affects older leaves
  • Verticillium (Verticillium dahliae)
  • Leaf spots (Early Blight or Target Spot)
  • Root rot
  • Mosaic virus results in mottling
  • Aphids
  • Spider-mites can cause a white-yellow speckling

Light green

  • Too much nitrogen
  • A lack of manganese


  • A lack of iron
  • Powdery Mildew results in powdery patches


  • Fusarium Crown Rot

Curling leaves

  • A lack of potassium affects older leaves
  • A lack of iron
  • A lack of copper is rare, but results in blue-green flappy leaves
  • Curly Top virus affects upper leaves and results in a purple-like color

Spots on leaves


  • Early Blight or Target Spot (Alternaria solani)
  • Late Blight (Phytophthora infestans)


  • Bacterial Speck (Pseudomonas syringae)
  • Bacterial Spot (Xanthomonas campestris pv vesicatoria)


  • Late Blight (Phytophthora infestans)
  • Tomato Spotted Wilt/Impatiens Necrotic Spot Tospoviruses

Wilting leaves

  • Fusarium (Fusarium oxysporum f.sp. lycopersici)
  • Fusarium Wilt
  • Fusarium Crown Rot
  • Verticillium (Verticillium dahliae) can result in wilting at midday but recovery at night
  • Bacterial wilt (Ralstonia solanacearum)
  • Root rot
  • Tomato Spotted Wilt/Impatiens Necrotic Spot Tospoviruses (TSWV or INSV)
  • Nematodes causes the plant to wilt prematurely
  • Walnut toxicity if the plants grow near a walnut tree

Drooping leaves

  • Fusarium (Fusarium oxysporum f.sp. lycopersici)
  • Fusarium Wilt
  • Fusarium Crown Rot

Flies on leaves

  • Whitefly (1 mm), more often seen in a greenhouse than out in the open
  • Thrips (1 mm), onion thrips (Thrips tabaci) and flower thrips (Thrips obscuratus)
  • Fruit fly

Removing some of the leaves

If the problem is that you have too many tomato plant leaves then here are some tips on removing some of the leaves to provide the plants with more sunlight and oxygen:

  • Single vine variety: All ‘suckers’ can be removed and staking should first be done after the first flowers appear to create a strong plant.
  • Multi-stemmed variety: All stems should have the same size. Any side stems below the first flower cluster can be removed to create a strong main stem.
  • Determinate variety: ‘Suckers’ below the first flower cluster can be removed.
  • Sterilize knife or scissors between plants, or use your fingers to pinch of unwanted leaves and branches
  • Remove branches during dry days to avoid bacteria getting into the ‘wound’ because of rain
  • Remove sick leaves and branches to reduce spreading of diseases
  • You can reuse any clippings – they will grow into new plants if you stick them into the soil!

Cucumber leaves

I haven’t been able to find any evidence saying that tomato plants can’t rub leaves with cucumbers. I think it’s a myth and more a question about space. Cucumbers grow big leaves, and they could overshadow a tomato plant if the plants were standing close.

While it should be safe to grow cucumbers near tomatoes, there are some plants that are even recommended companion plants for tomatoes, like French marigolds (Tagetes patula), because they deter nematodes. Other plants that act as pest control are:

  • Basil
  • Chives
  • Parsley
  • Onions


How to Grow Juicy Tasty Tomatoes by Lucia Grimmer and Annette Welsford

Natural Bean Plant Trellis for Runner Beans

I didn’t have much outdoor space for growing food this year but I spotted these two self-seeded young trees and got the idea of using them as bean trellises:

It’s a bit difficult the see the bean plants climbing up the stems, but you can tell that there’s a bean plant in there somewhere because the leaves are light green instead of dark green. The bean plant growing on the tree to the left is even harder to spot since this is a purple bean plant variety.

I planted each bean plant in their own clay pot below the trees:

If I hadn’t used the young trees as bean trellises for runner beans they would probably have been cut down, because they were self-seeded. It turns out that as these trees grew taller they actually shielded my small container garden pretty well from the wind, which is important, or else your tomato plants and cucumber plants might easily be ripped apart during a storm.

A close-up picture of one of the stems clearly shows that there’s a bean plant growing on the stem:

And as usual – the bean plant is growing counter-clockwise around the stem or trellis. And no, it’s not related to your geographical location, i.e. if you’re living on the northern or southern hemisphere.

Small green beans have started to form and more flowers are developing so soon I’ll be able to harvest something for the kitchen!

Aquaponic Tomato Plants

I took a break from my aquaponics project as I was getting discouraged by seeing the previous batch of seedlings dying a slow death on top of my aquaponics plant tank. It seemed like I had missed some important point in the process of growing aquaponic plants, so I actually drained the whole plant tank, cleaned it, and installed a traditional filter in the fish tank / aquarium to keep the pet fish happy. That’s how fed up I was with my aquaponics problems.

… But I soon got too annoyed with the empty plant tank and my unreached goal of bringing this beast into production mode, so I went outside an started cutting side branches off my large tomato plants that I’m growing in self-watering containers beneath the south facing wall of the house. I learned from the ebook “How to Grow Juicy Tasty Tomatoes” that cuttings from a mature plant will easily grow into new plants if you stick the cuttings into the soil. Fortunately it works with aquaponic coconut fibers too:

The cuttings grew into tall plants, actually a bit taller than I have room for beneath the ceiling. The maximum grow height available in this system is small since the fish tank must be placed beneath the plant tank, and the fish tank in this case is an ordinary aquarium which you what to place on an aquarium table to be able to enjoy the fish without having to lay down on the floor 😉

A quick look at the new tomato plants gives you the impression that they are healthy, and the stems and leaves have a healthy color:

But if you take a closer look at some of the largest tomato plants you’ll find that some of the leaves have wilted:

(WARNING: Oldest aquaponic joke coming up: “I’m sure I gave them enough water…” Ha. Ha.)

I have to find out what’s causing this, and even the small developing tomato flower stems are affected by this too. The leaves turn dry and crispy and turn into dust if you squeeze them.

I wouldn’t say that the submerged roots look particularly healthy:

Rasmus noticed the same brown stuff on the roots of my previous batch of aquaponic plants and recommended adding air bubbles directly to the plant tank. I think it helped back then but I forgot to reinstall the air pump after I cleaned up the plant tank.

Lots of challenges still with this relatively new aquaponics home system in the corner of my living room. And I’m still having wet dreams about adding automatic electronic measurement of pH and conductivity.

Aquaponics Tanks

When I think of an aquaponics tank I normally think of a rectangular container, which is like the aquaponics plant tank I built for myself, but take a look at these plant ‘tanks’, which are made from PVC tubes instead:

Photo by Kanu Hawaii.
These plant tanks, or plant grow beds, take up very little space and evaporation losses are very small. The nutrient rich fish water flows through the tubes providing the plants with what they need.

A whole wall has been covered with these plant tubes and connected to large aquaponics fish tanks:

Photo by Kanu Hawaii.
The fish in my system are also pet fish and live in an ordinary aquarium, so that you can see the fish, but I don’t think the fish actually care whether or not they’re able to look back at the people watching them. And if that’s true you might as well dump the fish in a big black plastic container as shown in the picture above. Just remember that black surfaces absorb energy from the sun and  heat up.

An aquaponic system can be installed anywhere, like for instance right next to a restaurant or hotel to secure an extremely fresh supply of herbs and vegetables:

Photo by Kanu Hawaii.
The system I built is based on an ebook called Aquaponics 4 You that originated from Hawaii (formerly known as Ultimate Aquaponics Home System) and the University of Waimanalo in Hawaii is experimenting with aquaponics too. Take a look at one of their neat plant tanks, with floats and net pots installed, standing on top of a few layers of cinder blocks:

Photo by Kanu Hawaii.

The area is packed with aquaponics tanks, and a solar panel would be a very convenient way of driving your water pump in an outdoor aquaponic system:

Photo by Kanu Hawaii.
Some kind of marquee placed above your tanks would be a good way to protect your crop against the weather if it’s necessary:

Photo by Kanu Hawaii.
When you’re building a system and looking for aquaponic supplies you can benefit from all the hydroponic containers on the market already. The large white tank below is from but all the pipes and fittings you could ever dream of is probably also available from the existing hydroponic retailers:

Photo by Kanu Hawaii.
I grow my aquaponic plants in coconut fiber but many people use LECA balls instead (Lightweight Expanded Clay Aggregate) – then you won’t need floats and net pots:

Photo by Kanu Hawaii.
Here’s another system installed under a large polytunnel cover, with an artificial fish pond beneath the plant pond:

Photo by Justin Leonard.
The next system has three layers – two layers of watercress beds and a 120 cm deep fish pond (4 feet) at the bottom. The beds are 120 cm wide (4 feet):

Photo by Justin Leonard.
The water circulates slowly through PVC pipes and the watercress filters the water for the fish:

Photo by Justin Leonard.
You can throw as much money as you have at an aquaponics system to keep improving it, but with very little money and reused materials you can get a cheap system up and running. The most expensive part is probably the pump but in small systems it shouldn’t take long to find someone who has a spare that you can have for free.

Photo by hurricanemaine.