"Only on edges do we see fertility"

A couple of years ago whilst shooting the Food Forest DVD with Geoff Lawton he remarked how “only on edges do we get fertility” or words to that effect. At the time that phrase didn’t really make much sense to me but when you stop and think for a moment how nature creates soil – those words begin to ring true.

We hear a lot about soil degradation and soil erosion but we hardly hear about simple methods of building soil – the positive solutions we can go about to build fertility  back into landscape.

According to Permaculture teacher Geoff Lawton, the fastest way to create soil is in shallow lakes and ponds through anaerobic activity.

Organic matter is transformed into soil – but its a slow natural process.

A decorative pond in your garden is more than just an ornamental feature or a place for frogs and fish to congregate. It can also be a soil creation mechanism as Geoff explains in this you-tube clip.

Seeing soils being created in the most unlikely places is something not many of us seem to notice but it does go on silently day in and day out usually in damp and dark places where the fertility of carbon and water is captured and held – the edge factor!

Apart from zinc-alum guttering, soil creation goes on in the most unlikely of places. Storm water drains and channels have some of the best soil found along the edges of culverts and overflowing creeks. Anywhere it seems where water can collect and organic matter be allowed to accumulate. It goes on silently drip by drip, leaf by leaf with the odd worm arriving to add his mark in his new home.

Originally we were going to include this clip in the Permaculture Soils DVD but we honestly ran out of space and time and there was plenty of other stuff we wanted to go through. There are faster ways to build soil and Geoff is confident that by harnessing a little moisture, nitrogen in the form of fertilizer and some carbon – you can actively make good quality soil in your garden and grow fresh food as well.

But spare a thought for edges – without them all that top soil would blow out to sea…

The term “swale” is often used by Permaculture people when designing large earth work constructions but it’s very rarely spoken of in an urban setting.

What is a swale anyway?

Well its commonly defined as “a water harvesting ditch on contour.”

Imagine it as a long wide cup rather than a gutter or drain. You can gain a better idea of how a swale functions by looking at the animation  here.

Drains are designed to get rid of water – fast.

Swales are designed to keep water from draining away too fast – they are meant to slow water down to a trickle and keep it from running away so it can be directed to where the water is needed most – keeping your garden plants moist and alive during the hot summer months.

In our Harvesting Water the Permaculture Way DVD we show how swales are created and attached to a dam system on a larger farm setting.

But what about the suburban backyard? Is a swale system needed at all?

Front Garden

Shooting the Urban Permaculture DVD with Geoff Lawton we came across a magnificent example of great mini swale design in a suburban setting in Sydney.

Here the front garden was surveyed and the contours planned to work with the natural slope of the land.

The roadway was higher then the house, so rain water was directed to flow from the footpath – through two mini swale walkways that fed the front vegetable garden beds and distributed the water out to the backyard.

The roof on the main house also collected rain in a large water tank and directed excess water to a large barrel that was hidden inside the boundary hedge. The barrel would collect and distribute overflow water directly into a small frog pond.

Having water tanks hidden inside a boundary hedges, eliminated seeing their functional industrial look and helped to distribute water runoff around various points in the garden.

In a rain event , the frog pond would overflow and spill water into the top swale and soak water slowly into the top garden beds where the water would seep through to an adjacent swale walkway that would similarly soak the water out into the garden and keep it actively employed in the backyard for as long as possible.

This way, what little water fell on this backyard was used to the benefit of all the garden plants.

The mini swale paths were originally planted out with thick newspapers, heaps of Sunday Editions were used to smother weeds and act as a rotting mulch layer for top dressed tan bark that was layered above to not only  look attractive and easy to walk on but to also absorb any excess moisture.

“This is the type of design elements we have to include in all our designs,” says Geoff Lawton, “so we get the best result. Minimum of input, Maximum Output.”

A garden like this requires minimum maintenance throughout the seasons.

“We have contour layers designed into the garden so the water slowly soaks through.” said Geoff Lawton.

As the water runs down the garden it feeds a larger pond which is powered by a little solar powered pump that creates the feel of a natural water fall near the main entry point to the house.

Excess water from this pond helps to direct moisture to the backyard behind the house.

Backyard Garden Swale System

Geoff Lawton sitting in a mini swale backyard system

The grey-water system in the backyard collects all the water runoff  from the kitchen into another little frog pond positioned in the right top corner of the backyard.

Here the water soaks into the heavily mulched swale trench system that runs adjacent to the house as it loops around an island garden bed to feed an assortment of productive fruit trees.

The island also has its own little pond hidden amongst the overhanging fruit trees.

The owner  of this garden has also planned for a chicken coop to be positioned along the boundary fence which will also collect any chicken nutrient runoff and distribute it into the system.

Backyard Swales direct Grey Water through Garden

By organizing your suburban backyard into a cascading series of mini swales that help direct water runoff throughout the garden, making it soak into garden beds under the mulch at the root zone will enable you to grow all your vegetables and fruit with minimal additional water. Excess water will also keep the frog ponds active and invite nature back into the garden. It does take a certain amount of Permaculture study, planning and thinking to achieve such a result.

But the end results are well worth the effort as the system matures one can feel the garden merge back with nature even when living in the middle of a heavily urbanized environment.

This garden will be featured in the Urban Permaculture DVD out later in the year that goes into a lot more depth than this blog post allows.

Geoff Lawton peels back a clump of reeds in an urban greywater reedbed in suburban Sydney

Permaculture teacher Geoff Lawton scrambles through a clump of reeds perched over a some large boulders and gingerly steps over a pond choked with Duckweed and Salvinia floating on the surface. You can hear the frogs croaking in the background. Birds are singing in the trees. He peels back a clump of papyrus reeds to reveal another  hidden frog pond.

You may think this is a scene taken from a wilderness somewhere in a thriving jungle. But its not. We’re in a suburban Sydney backyard. A yard no bigger than most you’ll find anywhere. But its not a normal backyard. Its a Permaculture garden with its own little wetland.

Building a wetland in your backyard is not something many people would ever consider – except if you’re into Permaculture.

Penny Pyett’s home has a wonderful grey-water reed-bed system that looks complicated at first but is so simple to design into your garden and the benefits are many.

Apart from encouraging native frogs and wetland creatures to return, its a channel for all household grey water waste. No dumping of water back into the storm water drain and out to sea here. Penny is using her waste water for productive ends. When the water is cleaned through a series of gravel reed beds and filtered through a series of frog ponds – it gets fed to her fruit trees.

Penny has got a food forest of productive trees that are also fed by the nutrient waste from ducks. Thats right! Ducks in the City. You need ducks to keep eating those fat little frogs you have growing in your reed bed – right? Thats all part of the Permaculture philosophy after all. But we’re getting ahead of ourselves here so lets jump back and get back back on track.

Lets take a closer look Penny’s greywater system and take a look at her design.

All the greywater in the house is dumped into a header tank which is located under the house. In Penny’s case, it happens to be an old bathtub. The bathtub has a 45mm PVC pipe that runs underground to the desired spot for her three gravel reed beds. Course gravel is used to quickly soak any waste water and a series of thick reeds and boulders are used to hold the system in place should a sudden rain event or deluge occur.

Gravel

Any thick gravel is suitable preferably one that doesn’t have any limestone which will alter the pH. Wetland plants are designed to grow in waterlogged soils with very low oxygen levels. Most wetland plants are adapted to “pull oxygen out of the air” and diffuse it down through the roots creating little aerobic zones. This stimulates microbial activity and bacterial growth to occur. The bacteria will break down compounds suspended in the soil and help filter the water as it runs through the various gravel beds and out to the frog ponds. Microorganisms break down about 90% of pollutants and waste breakdowns in the gravel. The plants also act as a carbon source for microbe activity when they break down and decay.

A natural reedbed system

What Reeds are suitable?

Recycled ponds are buried and reused in a greywater system.

Plants able to be grown in permanent water swamps

• Persicaria lapathifolium Knotweed
• Ranunculus inundatus River Buttercup
• Phragmites australis Native Reed
• Restio tetraphyllus Tassel-rush, Tassel Cord-rush
• Triglochin microtuberosum Water Ribbons

Plants that are able to grow in fresh water swamps, creek and dam banks

• Carex appressa Tall Sedge
• Gahnia clarkei Tall Saw-sedge
• Gahnia melanocarpa Leafy Sedge
• Gahnia aspera Tufted Sedge
• Isolepis nodosa Knobby Club-rush
• Juncus kraussii Sea Rush
• Juncus usitatus Common Rush
• Lomandra longifolia Spiny-headed Mat-rush
• Dianella caerulea Blue FlaxLilly
• Crinum pedunculatum Swamp Lilly
• Cladium procerum Leafy Twig Rush

Frog Ponds

The grey water eventually drains into a small frog pond where small fish can also be added to keep the mosquito population under control. Penny Pyett likes to recycle a lot of materials thrown out by people back into her wetland. So discarded plastic children’s play pools and sand pits are collected and recycled by Penny into her wetland garden. Buried in the garden between thick reeds, they look natural and inviting. Water is constantly in play moving through the gravel and dipping from one large pond to another and so on. Eventually the water is returned clean and back into a swale that supports a food forest system. The end result is that you end up irrigating your garden every time you take a shower or wash the dishes. Nothing is wasted as the system takes care of itself.

Penny’s greywater reedbed system will be featured in The Urban Permaculture DVD out later in the year. Check it out.

Harvesting Water DVD

A while back when we made our first DVD on harvesting rainwater to drought proof your property we first came across this term “Swale.” What does it mean exactly and why do Permaculture people advocate its usage? If you asked Geoff Lawton from the Permaculture Research Institute what it meant he would give you the standard definition:

“A swale is a water harvesting ditch on contour with a soft mound on the lower slope.”

Swale contour map with the swale ditch marked in red

If that definition went over your head – you are not alone. The swale ditch must be excavated and perfectly aligned to follow the natural contour of the property.

It can be as long or short as you like. Some swale systems can run for many miles. It’s function is to slow the flow of water. To hold water for as long as possible, perfectly level for as long a time before it runs away.

Most engineering ditches deal with getting rid of water. Think of guttering on your roof or on the side of roads.

In Permaculture theory the principal is to slow the movement of water right down. To keep the flow moving slowly and allowing it to soak gently into the surrounding landscape and rehydrate the aquifers.

It can take a lot of active field work to become proficient in reading the rhythms of the landscape – but the principal is sound and if you use it cleverly on your land it can rehydrate a sizable property and replenish underground water springs and be a clever way to reforest a trashed environment with say – a food forest system that adds value, beauty and natural abundance to your property.

Its no wonder that many Permaculture consultants are asked to walk over farmland, define the best place to site a swale that connects to properly situated dams that have a spillway that directs water where it can be put best to work.

A swale to work best must be sited exactly on contour. Hiring the services of a laser level might be an easier choice to peg out the natural contour on your property but knowing where to site the swale and dam system is an art that takes many factors into consideration.

Australia with its long periods of drought, followed by heavy downpours sees most water run off the landscape very quickly leaving the substrata still dry.
This is where the landowner during periods of drought should plan their water harvesting infrastructure very carefully to make the maximum use of every drop of rainwater that falls during the big wet periods.

At Mulloon Creek near Canberra Australia, Geoff Lawton built 2 kilometers of swales that feed into a network of dams that help drought-proof the valley.

A swale after a downpour at Mulloon Creek

The swales help to recharge water back underground where it can be “banked” for later usage during the inevitable dry periods that can last many years as well as feeding back into the neighbouring creek system sending water down steam to other farms.

The advantage of swales is that you can also plant a food forest system on the lower mound side where the water will gradually seep away. A Food Forest will build you a canopy of trees, reintroduce native flora and fauna and generally stabilize fragile eco-systems.

This DVD looks at a small acreage farm and follows Permaculture teacher Geoff Lawton and a team of students as they consult with a client, survey the landscape and discuss the best way to capture rainwater and divert it into a series of swales to feed a dam system that they will construct over the course of three days. This DVD explains each step of the way and is a good introduction to Permaculture Earthworks construction and explains the basics of good design to harvest water passively as well as potential problems with excavation and how to deal with those issues. This DVD ends when the swale and dam system is completed. See our Establishing a Food Forest DVD on how to plant on the swale system and grow abundant food once your earthworks is in place. Video duration is approximately 70 minutes with a number of extras including an extended interview with Geoff Lawton’s “Greening the Desert” video and a look at Permaculture Earthworks systems around the globe.