Great article I want to set up wicking beds as we are on tank water. Would it also help to protect vegetables from frost as we live in a cold area where we can occasionally get snow. Keep up the good work
Hi Heather, using wicking beds will potentially alter the microclimate slightly. We are very prone to frost here in Kyneton. I find the raised beds tend to suffer less frost damage (frost sinks, and is heaviest at ground level). The difference is minimal, but can help you make a slightly earlier start.
Hi Duncan, while this is some time after your article, I thought you may be interested. Mid December, I took delivery of two Biofilta wicking beds and have been delighted with them. Easy to assemble and highly effective. While the 70mm of rain we've had here in the past month has interfered with my calculations, I reckon there's 6-8 weeks in the reservoir for a full bed of leafy greens in moderate/warm conditions. The lightweight (30%) shade cloth allows sufficient sun in for growth but prevents wilt, and keeps the cabbage whites out. Not cheap, but very good. One needs to remember to keep checking the plants for pests etc. I'm using land cress for the cabbage whites, which seems to be effective.
Good to hear your experience with wicking beds. I'm intrigued by your apparent success with land cress to control white cabbage butterfly. My research indicates that it is a sacrificial crop not a dead end trap crop as some folks believe. That is, the land cress attracts the butterflies but does not kill the caterpillars feasting on it.
In your case, I think your shade cloth is proving to be an effective control.
Excellent article. I have moved on from all that though and now use repurposed bathtubs as wicking beds. No pond liner required. I just invert the waste pipe and cover it with shade cloth. But bathtubs are ugly right ? I just use fence palings as skirts around the unsightly tubs and mulch over the exposed rims and they look like timber planters. I have been doing this for a few seasons now and they work brilliantly. And they didn’t cost a penny. As a bonus I have drilled holes through the rims and arched electrical conduit over the tubs to support netting. I had to move during lockdown so I emptied the tubs and took them with me. Try doing that with conventional wicking beds !
Bathtubs can make great wicking beds. Although they are a touch shallow (but only just). It certainly a cheap and efficient method to make a wicking bed. As you mention they are also fairly portable.
Thanks for sharing your experience and technique with us Jamie.
It's a long watch (I'd recommend skipping to time 44:02 for the summary), but the video "Wicking Bed Design Webinar" from the channel Small Farms Network Capital Region on Youtube talks about how someone did their PhD on which wicking materials and setup work best. For anyone who might be reading this and interested
I have eight wicking beds. They were installed for me when l had an accessible garden installed. As a wheelchair gardener l have found the Food Cube in the slim( so l can retch from my chair )l am so impressed by Biofilta’s Foodcube. One of the good features for me is the automatic watering system .. as all the cubes are linked and l don’t have to worry due to health if l can’t water in the summer . It’s easy if there is too much rain too … there is an overflow.
It has really helped me get back to the garden after my mobility changed
Thanks for this interesting article. I have a small commercially made wicking bed to grow strawberries in, hoping to keep it weed free and avoid snails, earwigs, birds etc from getting to the strawberries before me...a very expensive way to get to eat my strawberries, I know! Is it OK to water from the top, or do I need to water straight into the reservoir?
Thanks for your question and great feedback. In terms of the wicking bed functionality, either option for watering is fine. In fact, for newly planted seedlings and seeds sown directly, you'll need to water form the top for the first week or so.
However, watering established plants from the top, especially when the foliage gets wet, increases humidity and the risk of pests and diseases (more on this in an upcoming post). Watering strawberries plants from above could especially lead to an increase in slugs and white fly. We normally have huge issues with the slugs destroying our strawberry fruit in spring (ie now) but as soon as the weather dries up in late November, we have virtually no slug damage.
Once established, I'd be watering the strawberries via the reservoir.
Thanks for your kind words. I'm sure you're right about the builders film - I'll be looking into a pool liner for the next one, if I can afford it! The builder's film certainly requires more care and protection.
Some years ago, a group of us built a small wicker at the local Craft Cottage, using a steel edging ('Birdy' raised bed edging, from memory) and some donated pre-used swimming pool liner. That was a struggle! It was very stiff. Maybe new liner would be more co-operative... I don't think we managed to seal around the outlet properly; and certainly the nearby oak trees' roots had a good go at getting into it, probably through said seal.
It was successful for 2 years, then was removed for other reasons.
Hi Duncan, Once again a great beginner's guide to wicking beds! Possibly the only way to grow good greens in the drought we may soon be having, and near trees with invasive roots (ie, all trees!)
I'd like to add a couple of comments, starting from the bottom up, so to speak.
1. Very important to level the site before you start to build - otherwise the water pools at one end, leaving the other dry. I levelled the site originally with a scraper/hoe and spirit level, but an earth mover and laser will be much easier if you can afford it.
2. The sides. The same applies here as for raised beds - the longevity of the sides determines the longevity of your wicking bed. For my first bed, I used any scrap planks I could find, held up with star pickets; this lasted quite well for 3 - 4 years, then fell apart. Even cedar (cheaper grades) will start to rot within 5 years - that's what my professionally built bed is doing now. Brick or stone, properly laid, should last a lifetime; colourbond (corrugated metal) likewise, though it may make the outlet a bit more complicated to design.
3. The reservoir liner. All my 'wickers' are lined with 0.2mm Builder's film, because I had no money, but was gifted a roll of the stuff! Though easy to install, it has its problems, as you say. UV shouldn't be a problem though, as the liner is underground, mostly. But yes, it must be protected above and below from piercing by sticks, stones, scoria etc. I had plenty of empty feed bags, so I used those above and below the liner to protect it. This seems to have worked well.
One extra hint - After adding a little of the scoria, add a few inches of water. This will push the liner well into the corners, before there is extra strain on it from the full weight of everything that will be above it. This will prevent leaky corners...
4. The geotextile membrane. Old 75% shadecloth can substitute at a pinch! You might like to add a layer of weathered wood chip on top of that to help a bit more. Then, over that, a growing medium high in organic material - no sand or clay, as their particles are finer and will wash down into the reservoir more easily. Rotted horse manure, with worms from the worm farm, work well for me, and leaf mould for the blueberries.
5. Depth of scoria? Mine is about 10cm, but could be 20cm. Not much point having it much deeper than that, as there is a limit to how high capillary action can 'pump' the water upwards. Too deep, and you could have a permanent pool of water down there, which may lead to stagnation problems. My system has never had those. I do let the reservoir empty (ie, 'breathe in') before refilling! I check the level with a 'dipstick' in the inlet pipe.
6. Mulch - aim for 10cm of mulch on top, especially in summer when evaporation is highest. Both the growing medium and the mulch should be topped up once or twice a year, between crops. Just like an in-ground bed really.
7. What to grow in a wicking bed? Beans, peas, any green leafy things, brassicas, cucumbers, shorter varieties of carrots and parsnips, beetroot, bush-type tomatoes, blueberries, strawberries, maybe gooseberries (haven't tried them yet.) Especially in droughts!
8. What NOT to grow? * Onions, garlic etc that actually need to dry out in summer;
* Invasive things - though raspberries, red currants and so on, do very well in their own dedicated wicker;
* Things that need to be dug out with a fork (lookin' at you, potatoes);
* Very long varieties of carrot & parsnip, and very deep rooted plants. Trees!
* Hungry, thirsty takeover merchants such as pumpkins, sweet corn and runner beans - they'll love a wicking bed to death...
Hey, I hope these ramblings are helpful, and not too nerdy. I suppose it all comes back to money, and how well the bed is built in the first place. The longer the bed lasts, the more it spreads out the cost.
Wow.... what an insightful, thoughtful and rather epic comment. Thanks for sharing all that wisdom and experience. It is invaluable advice for anyone going to try their hand at DIY wicking beds.
I've re-read your comments at least three times now and goodness they are comprehensive. The only follow up comment I have is regarding the builders film. I really don't recommend it. I have emptied a few wicking beds now that were constructed with builders film. I am certain that some of the holes in them were caused by something chewing through the builders film. I could never identify what, but it was not a normal puncture mark from scoria or gravel etc. Even though the liner is not exposed to light, it does tend to break down and become brittle quite quickly compared to the better quality stuff. Certainly, you could have many years of good use from a wicking bed constructed from builder's film, but I've also seen many fail. I've never seen a wicking bed fail when constructed with a heavy duty liner.
Thanks again for taking the time to share your thoughts. It's amazing!
Used a wicking garden for my Berry patch and they did really well...because they could access as much water as they wanted...they used heaps. We made some at school...mini ones, out of Styrofoam boxes and left over pieces of shade cloth and hose ends. Worked really well to grow herbs and flowers...and even lasted over a five week holiday break from an occasional shower that topped them up a bit.
Raspberries and other cane berries should do really well in a wicking bed. I've seen mini wicking beds made from plastic tubs and other similar materials, as you have done with the Styrofoam.
Living in the arid centre of Australia, wicking beds are great for backyard gardeners who may not be around everyday to water their garden, particularly in summer. While inputs and effort are required, wicking beds protect the vegie garden from thirsty tree roots. I have constructed a number of wicking beds over the years and have found that quality builders plastic folded over in two is a viable alternative to pond liner, which at my most recent garden bed lasted almost 7 years without breaking down. I cover the pipe, which has drilled holes along its length with gravel/crushed rock, then a layer of geofabric. I then have an equally deep layer of river sand which aids the wicking action into the soil. The outlet pipe is added at the top of the sand layer eg. 15cm rock, 15cm sand and 30cm growing soil. Wicking beds are ideal for people who may be away from time to time and unable to water their garden often. I love Wicking beds and swear by them up here in central Australia but can see the potential downsides where water availability, evaporative loss and extreme heat are not issues.
Thanks for sharing your thoughts. I'm glad you've found wicking beds useful for preventing tree root invasion. In this part of the world (SE Australia) I have found that the builders film is often chewed through by some invertebrate. I may be wrong on that, but I have carefully deconstructed a few leaking wicking beds now and found them to have lots of small holes that look like they have been chewed through. Whatever is causing the holes doesn't manage to get through the pond liner though.
It's an interesting approach using the sand. I like that you have the gravel underneath to enable the water to flow more readily.
Great article I want to set up wicking beds as we are on tank water. Would it also help to protect vegetables from frost as we live in a cold area where we can occasionally get snow. Keep up the good work
Hi Heather, using wicking beds will potentially alter the microclimate slightly. We are very prone to frost here in Kyneton. I find the raised beds tend to suffer less frost damage (frost sinks, and is heaviest at ground level). The difference is minimal, but can help you make a slightly earlier start.
Happy Gardening
Duncan
Hi Duncan, while this is some time after your article, I thought you may be interested. Mid December, I took delivery of two Biofilta wicking beds and have been delighted with them. Easy to assemble and highly effective. While the 70mm of rain we've had here in the past month has interfered with my calculations, I reckon there's 6-8 weeks in the reservoir for a full bed of leafy greens in moderate/warm conditions. The lightweight (30%) shade cloth allows sufficient sun in for growth but prevents wilt, and keeps the cabbage whites out. Not cheap, but very good. One needs to remember to keep checking the plants for pests etc. I'm using land cress for the cabbage whites, which seems to be effective.
Hi Alan,
Good to hear your experience with wicking beds. I'm intrigued by your apparent success with land cress to control white cabbage butterfly. My research indicates that it is a sacrificial crop not a dead end trap crop as some folks believe. That is, the land cress attracts the butterflies but does not kill the caterpillars feasting on it.
In your case, I think your shade cloth is proving to be an effective control.
Happy gardening
Duncan
Excellent article. I have moved on from all that though and now use repurposed bathtubs as wicking beds. No pond liner required. I just invert the waste pipe and cover it with shade cloth. But bathtubs are ugly right ? I just use fence palings as skirts around the unsightly tubs and mulch over the exposed rims and they look like timber planters. I have been doing this for a few seasons now and they work brilliantly. And they didn’t cost a penny. As a bonus I have drilled holes through the rims and arched electrical conduit over the tubs to support netting. I had to move during lockdown so I emptied the tubs and took them with me. Try doing that with conventional wicking beds !
Bathtubs can make great wicking beds. Although they are a touch shallow (but only just). It certainly a cheap and efficient method to make a wicking bed. As you mention they are also fairly portable.
Thanks for sharing your experience and technique with us Jamie.
Happy Gardening
Duncan
It's a long watch (I'd recommend skipping to time 44:02 for the summary), but the video "Wicking Bed Design Webinar" from the channel Small Farms Network Capital Region on Youtube talks about how someone did their PhD on which wicking materials and setup work best. For anyone who might be reading this and interested
I'm not sure if links are allowed, but here it is for convenience if that's ok https://youtu.be/O4aRMh_yRQk?si=XPsSw1543NIEgrIi
Hi Cat,
Thanks for sharing this resource.
Happy gardening
Duncan
I have eight wicking beds. They were installed for me when l had an accessible garden installed. As a wheelchair gardener l have found the Food Cube in the slim( so l can retch from my chair )l am so impressed by Biofilta’s Foodcube. One of the good features for me is the automatic watering system .. as all the cubes are linked and l don’t have to worry due to health if l can’t water in the summer . It’s easy if there is too much rain too … there is an overflow.
It has really helped me get back to the garden after my mobility changed
Thanks for sharing your experience with us Nola. I'm glad that you have found the Foodcubes to be beneficial for you.
Thanks for your support and happy gardening
Duncan
Thanks for this interesting article. I have a small commercially made wicking bed to grow strawberries in, hoping to keep it weed free and avoid snails, earwigs, birds etc from getting to the strawberries before me...a very expensive way to get to eat my strawberries, I know! Is it OK to water from the top, or do I need to water straight into the reservoir?
Hi Stephanie,
Thanks for your question and great feedback. In terms of the wicking bed functionality, either option for watering is fine. In fact, for newly planted seedlings and seeds sown directly, you'll need to water form the top for the first week or so.
However, watering established plants from the top, especially when the foliage gets wet, increases humidity and the risk of pests and diseases (more on this in an upcoming post). Watering strawberries plants from above could especially lead to an increase in slugs and white fly. We normally have huge issues with the slugs destroying our strawberry fruit in spring (ie now) but as soon as the weather dries up in late November, we have virtually no slug damage.
Once established, I'd be watering the strawberries via the reservoir.
Thanks for your support and happy gardening
Duncan
Hi Duncan,
Thanks for your kind words. I'm sure you're right about the builders film - I'll be looking into a pool liner for the next one, if I can afford it! The builder's film certainly requires more care and protection.
Some years ago, a group of us built a small wicker at the local Craft Cottage, using a steel edging ('Birdy' raised bed edging, from memory) and some donated pre-used swimming pool liner. That was a struggle! It was very stiff. Maybe new liner would be more co-operative... I don't think we managed to seal around the outlet properly; and certainly the nearby oak trees' roots had a good go at getting into it, probably through said seal.
It was successful for 2 years, then was removed for other reasons.
Cheers, Rose
Hi Rose, yes, think pond liner or potable grade liner can be a bit of a wrestle to smooth into position.
Happy gardening
Duncan
Hi Duncan, Once again a great beginner's guide to wicking beds! Possibly the only way to grow good greens in the drought we may soon be having, and near trees with invasive roots (ie, all trees!)
I'd like to add a couple of comments, starting from the bottom up, so to speak.
1. Very important to level the site before you start to build - otherwise the water pools at one end, leaving the other dry. I levelled the site originally with a scraper/hoe and spirit level, but an earth mover and laser will be much easier if you can afford it.
2. The sides. The same applies here as for raised beds - the longevity of the sides determines the longevity of your wicking bed. For my first bed, I used any scrap planks I could find, held up with star pickets; this lasted quite well for 3 - 4 years, then fell apart. Even cedar (cheaper grades) will start to rot within 5 years - that's what my professionally built bed is doing now. Brick or stone, properly laid, should last a lifetime; colourbond (corrugated metal) likewise, though it may make the outlet a bit more complicated to design.
3. The reservoir liner. All my 'wickers' are lined with 0.2mm Builder's film, because I had no money, but was gifted a roll of the stuff! Though easy to install, it has its problems, as you say. UV shouldn't be a problem though, as the liner is underground, mostly. But yes, it must be protected above and below from piercing by sticks, stones, scoria etc. I had plenty of empty feed bags, so I used those above and below the liner to protect it. This seems to have worked well.
One extra hint - After adding a little of the scoria, add a few inches of water. This will push the liner well into the corners, before there is extra strain on it from the full weight of everything that will be above it. This will prevent leaky corners...
4. The geotextile membrane. Old 75% shadecloth can substitute at a pinch! You might like to add a layer of weathered wood chip on top of that to help a bit more. Then, over that, a growing medium high in organic material - no sand or clay, as their particles are finer and will wash down into the reservoir more easily. Rotted horse manure, with worms from the worm farm, work well for me, and leaf mould for the blueberries.
5. Depth of scoria? Mine is about 10cm, but could be 20cm. Not much point having it much deeper than that, as there is a limit to how high capillary action can 'pump' the water upwards. Too deep, and you could have a permanent pool of water down there, which may lead to stagnation problems. My system has never had those. I do let the reservoir empty (ie, 'breathe in') before refilling! I check the level with a 'dipstick' in the inlet pipe.
6. Mulch - aim for 10cm of mulch on top, especially in summer when evaporation is highest. Both the growing medium and the mulch should be topped up once or twice a year, between crops. Just like an in-ground bed really.
7. What to grow in a wicking bed? Beans, peas, any green leafy things, brassicas, cucumbers, shorter varieties of carrots and parsnips, beetroot, bush-type tomatoes, blueberries, strawberries, maybe gooseberries (haven't tried them yet.) Especially in droughts!
8. What NOT to grow? * Onions, garlic etc that actually need to dry out in summer;
* Invasive things - though raspberries, red currants and so on, do very well in their own dedicated wicker;
* Things that need to be dug out with a fork (lookin' at you, potatoes);
* Very long varieties of carrot & parsnip, and very deep rooted plants. Trees!
* Hungry, thirsty takeover merchants such as pumpkins, sweet corn and runner beans - they'll love a wicking bed to death...
Hey, I hope these ramblings are helpful, and not too nerdy. I suppose it all comes back to money, and how well the bed is built in the first place. The longer the bed lasts, the more it spreads out the cost.
Cheers, Rose
Wow.... what an insightful, thoughtful and rather epic comment. Thanks for sharing all that wisdom and experience. It is invaluable advice for anyone going to try their hand at DIY wicking beds.
I've re-read your comments at least three times now and goodness they are comprehensive. The only follow up comment I have is regarding the builders film. I really don't recommend it. I have emptied a few wicking beds now that were constructed with builders film. I am certain that some of the holes in them were caused by something chewing through the builders film. I could never identify what, but it was not a normal puncture mark from scoria or gravel etc. Even though the liner is not exposed to light, it does tend to break down and become brittle quite quickly compared to the better quality stuff. Certainly, you could have many years of good use from a wicking bed constructed from builder's film, but I've also seen many fail. I've never seen a wicking bed fail when constructed with a heavy duty liner.
Thanks again for taking the time to share your thoughts. It's amazing!
Happy Gardening!
Duncan
Used a wicking garden for my Berry patch and they did really well...because they could access as much water as they wanted...they used heaps. We made some at school...mini ones, out of Styrofoam boxes and left over pieces of shade cloth and hose ends. Worked really well to grow herbs and flowers...and even lasted over a five week holiday break from an occasional shower that topped them up a bit.
Raspberries and other cane berries should do really well in a wicking bed. I've seen mini wicking beds made from plastic tubs and other similar materials, as you have done with the Styrofoam.
Thanks for sharing your insights Judy.
Happy Gardening
Duncan
Living in the arid centre of Australia, wicking beds are great for backyard gardeners who may not be around everyday to water their garden, particularly in summer. While inputs and effort are required, wicking beds protect the vegie garden from thirsty tree roots. I have constructed a number of wicking beds over the years and have found that quality builders plastic folded over in two is a viable alternative to pond liner, which at my most recent garden bed lasted almost 7 years without breaking down. I cover the pipe, which has drilled holes along its length with gravel/crushed rock, then a layer of geofabric. I then have an equally deep layer of river sand which aids the wicking action into the soil. The outlet pipe is added at the top of the sand layer eg. 15cm rock, 15cm sand and 30cm growing soil. Wicking beds are ideal for people who may be away from time to time and unable to water their garden often. I love Wicking beds and swear by them up here in central Australia but can see the potential downsides where water availability, evaporative loss and extreme heat are not issues.
Hi Jimmy,
Thanks for sharing your thoughts. I'm glad you've found wicking beds useful for preventing tree root invasion. In this part of the world (SE Australia) I have found that the builders film is often chewed through by some invertebrate. I may be wrong on that, but I have carefully deconstructed a few leaking wicking beds now and found them to have lots of small holes that look like they have been chewed through. Whatever is causing the holes doesn't manage to get through the pond liner though.
It's an interesting approach using the sand. I like that you have the gravel underneath to enable the water to flow more readily.
Thanks for sharing your thoughts.
Happy gardening
Duncan