How to make a Wicking Bed the Very Edible Gardens way

In a sea of confusing DIY guides and wicking bed misinformation, Very Edible Gardens is your beacon of professional and reliable expertise in wicking bed installations. With hundreds of successful projects completed in and around Melbourne and thousands of DIY kits sold Australia wide, we’re committed to saving you time, money and headaches by equipping you with the knowledge on how to get it right the first time. If you’re tired of wading through the murky waters of ‘how to make a wicking bed?’ you’ve found your safe harbour with us.

Option 1: Get In Touch With Us

The easy way if you live in Melbourne:
Let us create your new garden

We do the heavy lifting

We source the best products

Attention to detail

No Leaks

Creating a sustainable, bountiful garden can be daunting, especially if you’re new to wicking beds. Our friendly, passionate team brings extensive experience and great attention to detail, ensuring your wicking bed installation is done right the first time.

We’re proud of the positive feedback we continuously receive from our clients. It’s a testament to our commitment to providing exceptional service and quality. With VEG, you don’t have to worry about common installation issues like leakage or improper wicking. We’re so dedicated to getting it right that we often get called to fix installations done by others.

Option 2: Do It Yourself

Firstly, no matter where you are in the world, you can freely access and apply our unique process for installing wicking beds as outlined below. It’s designed to help you navigate the process with ease and confidence. 

Conversion kits for existing garden beds

Secondly, for our friends in Australia, we offer our VEG Wicking Bed Conversion Kits. These kits come with detailed instructions and all the necessary components, empowering you to convert or build your first wicking bed with the assurance that you have the right materials at hand.

View our range here.

Timber kit set garden beds in Melbourne

For those in Melbourne, we go a step further. We can deliver our popular kitset timber beds, along with the wicking bed conversion kits, in standard or custom sizes. These kits come with detailed instructions, the right drill bits, and other essential items you might need to kickstart your new garden project without delay.

Custom sized timber beds

 

Ready to embark on your wicking bed journey? Head to our shop page or keep scrolling to see our process.

How to make a Wicking Bed the VEG way: A step by step guide

Now that we’ve got that out of the way, let’s dive into the process. Don’t be overwhelmed by the details in the following diagram of a VEG-style wicking bed. We’ll guide you through each part of the process, step by step, in the sequence we use for our installations.

Step 1: Construct Your Raised Bed

the timber frame of the wicking bed
Construct a sturdy timber frame garden bed.

The initial step in building a wicking bed is to construct the raised bed, which will serve as the container for the water, soil, and plants. This bed can be made from a variety of materials, depending on your preferences and what’s available to you.

What do we use?

At Very Edible Garden, we use cypress macrocarpa sleepers timber sleepers to create a raised bed that’s typically 40 or 60cm high. This type of timber is light, durable and aesthetically pleasing, making it an excellent choice for a garden bed. And if you are in the Southern parts of Australia it’s an ethical choice.

Other types of timber?

Alternatively, and if sustainability is a priority for you, consider using reclaimed or salvaged timber. This approach not only reduces waste but also adds a unique, rustic charm to your garden. Each piece of reclaimed timber carries its own story, making your garden bed truly one-of-a-kind.

What about metal beds?

However, you’re not limited to timber. Solid corrugated iron garden beds are another fantastic option. They’re sturdy, long-lasting, and can lend a modern, industrial look to your garden.

If heading down this path, keep an eye on internal bracing that is too low and can not be removed and make sure the profile of the metal has an outlet adapter to match, more on that later.

Regardless of the material you choose, the key is to create a solid and secure structure that can hold the water and soil needed for a successful wicking bed.

The best way to build a raised garden bed

Without going into every minute detail, there are some key things that will give you the best outcomes when converting a raised garden bed into a wicking bed. 

  1. Keep the width manageable: for a single reach bed (access from one side), we stick to between 60cm and 90cm. For a double-reach bed (access from both sides) anywhere up to 1.4m wide works well.
  2. Make it strong: Use sturdy posts and correct bracing both on the verticle and horizontal planes. Drive screws into the face or edge grain instead of the end grain.
  3. Get it level: A level garden bed makes a great wicking bed. This ensures that the soil depth is consistent across the whole bed.

Step 2: Add a Waterproof Liner

schematic bed with liner
Carefully add the drinking water grade liner to create a water tight container for your screenings and soil.

The next step in the process is to lay down the liner. This is a crucial component of your wicking bed, as it holds the water that will be wicked up by your plants.

What sort of liner?

We recommend using a heavy-duty liner that is safe for contact with drinking water. While it might be tempting to opt for cheaper alternatives like builder’s plastic, these materials are easily punctured and can degrade quickly when exposed to sunlight. Investing in a high-quality liner will ensure the longevity and effectiveness of your wicking bed.

Any tips?

When installing the liner, proceed with caution. Even though the liners we use at Very Edible Gardens are robust and designed to withstand the elements, they’re not invincible. Before laying the liner, thoroughly check the bed for any sharp objects such as screws or shards of glass that could potentially puncture it.

Remember, a secure and undamaged liner is key to a successful wicking bed. So, take your time with this step, ensuring the liner is laid out smoothly and securely within your raised bed.

Step 3: Install the Plumbing

schematic with overflow pipe in
Add the inlet and outlet assemblies including the agi pipe.

With the liner securely in place, it’s time to add the inlet and outlet assemblies, along with the agi pipe. Correct installation of these components is crucial for the functionality of your wicking bed.

The outlet or overflow

Let’s start with the outlet. The outlet assembly is designed to let excess water escape from the reservoir, preventing over-saturation. Our innovative plumbing setup, which we developed and has since been replicated by others, serves three essential functions:

  1. Overflow Pipe: It prevents overfilling by allowing excess water to escape, ensuring your soil and plants aren’t waterlogged.

  2. Inspection Pipe: It allows you to easily check the water level in your wicking bed, taking the guesswork out of when to water your plants.

  3. Drainage Mode: By simply rotating the pipe, you can set your bed to ‘drainage mode’, a handy feature during wet winters or if you need to empty the reservoir for any reason.

Making holes in your watertight wicking bed!

To install the outlet, we first drill a hole through the side of the timber bed at one end. We then carefully cut a corresponding hole in the liner. The outlet plumbing assembly is then inserted through these holes. It then screws together and clamps securely in place. To ensure a watertight seal and prevent any potential leaks, we also apply a touch of silicone sealant between the two supplied washers. On the inside of the bed, we add a short 20cm length of agi pipe.

Why do you make the hole at the bottom of the bed?

Unlike other systems where the outlet sits at the same height as the top of the reservoir, our outlet pipe provides you with greater control and visibility over your wicking bed’s water levels. This unique feature is just another way we ensure your wicking bed is as efficient and user-friendly as possible.

The inlet or filler pipe

The inlet assembly is where you’ll add water to the reservoir. It’s typically a pipe that extends above the surface of the bed for easy access. It consists of a handy tap adapter to plug your hose onto that runs into a 1m length of  ‘agi pipe’.

Where do you put the inlet pipe?

To make monitoring the water level easier, we recommend placing the inlet pipe close to the tap and also in a position where you can view the outlet as you fill the bed. This way, you can easily monitor the water level and notice when it starts to overflow, indicating that it’s time to turn off the hose.

What about the agi pipe? Why doesn’t t run the full length of the bed?

The agi pipe, short for agricultural pipe, is a perforated tube that helps distribute the water throughout the reservoir. In a Very Edible Gardens wicking bed, the purpose of the agi pipe is to allow water to quickly fill the reservoir without backflooding up the inlet. It is not used to create a void to hold water.  Selecting the correct sized aggregate will take care of the water holding space. More on that in the next step.

Step 4: Creating the Reservoir

schematic with stones and more pipes
Fill your wicking bed with 7mm screenings or equivalent not 20mm scoria!

Efficient wicking is all about capillary action, a process that allows water to flow upwards against gravity, much like a sponge soaking up water. In a wicking bed, this action allows water from the reservoir to rise up into the soil and to the roots of your plants.

Why 7mm screenings?

Achieving efficient wicking requires a balance. The material in your reservoir (in our case, 7mm bluestone screenings) must hold enough water for your plants, but the size of the particles also affects how well the water can rise. If the particles are too large, the water may not rise sufficiently and if they’re too small, the water holding capacity will be reduced as well as having a wicking bed that may work too well!

Learn more about the science here.

Why we don’t recommend Scoria?

Despite its popularity, we don’t recommend using scoria, particularly the 10mm or larger sizes, in the bottom of your wicking bed. While this size scoria does have a large water-holding capacity, its wicking action or capillary rise is significantly lower compared to other smaller materials. This means that while it can store a lot of water, it’s not as effective at delivering that water to your plants’ roots.

Additionally, scoria often has sharp edges that can be uncomfortable to handle and potentially damaging to your liner. This risk, combined with its suboptimal wicking properties, makes scoria a less-than-ideal choice for your wicking bed’s water reservoir.

Step 5: Add Some Water and Find Level

Schematic with water filling
Use the water to get the screenings really level. Cut the outlet pipe so it's at the same level.

Now things are getting exciting – it’s time to bring water into the equation. Begin by filling your wicking bed with water until it’s just below the top of the screenings. 

Levelling your screenings

Next, give the screenings a rough level. To ensure an even surface, we suggest compacting the screenings slightly. If you have used one of our liners and also haven’t used something sharp like scoria, we recommend compacting by walking on them. Alternatively, squish them down with your hands.

Finally, use the water as a final levelling tool for the screenings. Your goal is to achieve a uniformly wet, flat surface that will serve as a sturdy foundation for your soil. You may need to adjust the water level until it’s just at the top of the screenings. The top layer of screenings should be glistening with moisture, but there should be no standing water or puddles. This ensures the perfect hydration level for your wicking bed without any dry or soggy spots.

Set your over flow height 

Now it’s time to adjust your outlet pipe. Cut it so that its top aligns with the water level, which should be at the top of the screenings. We use a pipe cutter for this step but you could also use a hack saw or some other cutting device. 

Your reservoir height is now set so that your soil won’t flood and go anaerobic. Learn more about that here.

Step 6: Adding the Soil

schematic wicking bed with everything including soil and seedlings
Add the geotextile fabric, the soil and the mulch and bam! your ready for planting.

Now that your water reservoir is ready, you might be eager to add the soil. But wait a moment…

How do we prevent the soil from falling into the water reservoir?

Begin by adding a layer of geotextile fabric over the screenings. This allows water to wick upwards while preventing soil from seeping down into the water reservoir. Other materials can be used here but it’s important to use a material that will not break down over time.

Time to get dirty

Next, add the soil. Ideally, you should use a fairly porous loam that isn’t too heavy in clay. This type of soil promotes good drainage and aeration, which are essential for healthy plant growth. 

We source a quality vegetable mix which is a blend of soil, manure, compost, organic matter and a few other beneficial goodies. 

 

As the icing on the cake top your soil with some organic mulch. Pea straw, Lucerne or our favourite Sugar Cane will all do nicely.  

 

Step 7: Planting and Managing Your Wicking Bed

Planting and maintaining a wicking bed is a breeze, requiring minimal effort. This simplicity is one of the many reasons why we, and countless others, are so fond of them.

Planting in your wicking bed follows the same basic principles as any other garden bed, but there are a few specific considerations to keep in mind. Let’s delve into these to ensure your wicking bed thrives.

Dry at the top and wet down bellow

It’s important to note that the soil near the surface of a wicking bed tends to be the driest. This is beneficial for weed prevention, but it also means that small seedlings may need additional watering for the first week or two until they overcome any transplant shock and their roots reach the moisture zone.

When do I refill my wicking bed?

The key here is to regularly monitor the water level in the reservoir during warmer weather. As a rough guide, when it drops to about 10cm below the soil level, it’s time for a refill. Simply attach a hose to the inlet pipe and fill until the reservoir overflows.

However, avoid the temptation to top it up daily as this could result in over-saturation. We’ve got through Melbourne summers topping them up no more than six or seven times. Moreover, resist the urge to over-water from the top. While it may seem beneficial, excessive top watering can wash away vital nutrients into the reservoir below and discourage your plants from extending their roots deeper into the more moist soil beneath.

Remember, use your plants as a visual indicator of water needs by keeping an eye out for signs of dehydration, such as wilting or drooping leaves.

What if it gets too wet?

During wetter times, it can be beneficial to switch your wicking bed to ‘drainage mode’. This involves adjusting the overflow pipe to the side slightly, which prevents the bed from becoming overly wet and effectively transforms your wicking bed into a drainage system.

What about climbing frames and stakes?

When it comes to supporting climbing plants, we recommend using A-frames, tee-pees or external structures affixed to the side of the bed, rather than long stakes driven deep into the soil. This avoids potential damage to your wicking bed geo fabric layer and in the worst case, your liner.

How do I fertilise and keep the soil fresh?

Like any healthy organic garden, you will need to feed your soil with manures and composts. In an annual vegetable garden, this is best done between seasonal rotations. 

In-ground worm farms have proven to be highly effective in wicking beds, serving as an excellent method for recycling nutrients through the system.

One thing to note is that you should be cautious with the use of nitrogenous nutrients, such as blood and bone. While these can still be used, excessive amounts can lead to leaching and stagnation in the reservoir. So, use them sparingly for the best results.

Want to learn more about Wicking Beds?

Get a Quote Today

Ready to experience the VEG difference? Fill in our wicking bed installation enquiry form for an estimated quote. Depending on various factors like location, site leveling requirements, or if a pre-work site visit is necessary, individual quotes may vary. We can usually book a site visit and installation date within one to four weeks.

Don’t delay your journey towards a more efficient, bountiful garden. Get in touch with VEG today – it’s as simple as that!

Once you click send you will be given the option to speed up the quoting process with our extended Wicking Bed Installation Quoting Form. 

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