Newsletter 25 March 2013
Soils for wicking beds
Colin Austin 25 March 2013
Many people think wicking beds are just
to save water; the most important feature however is
creating a mini ecology with a complex soil biology which
can release nutrients and trace elements in the soil so the
plants are rich in phytochemical to improve health.
This article shows how even poor soil can be
regenerated using soil biology.
does the public relations for soil?.
What a learning experience.
mystery of the dead chook – it took 65 years to solve.
Farming the soil biology.
Moisture the key.
Soil carbon and climate change.
Soil for wicking beds.
Rectifying your soil - structure.
Regenerating soil - chemistry.
Delusions of self sufficiency.
we be sure.
Regenerating soil - biology.
Feeding the soil biology is more complex.
Bringing it together
does the public relations for soil?
Dirty, boring, yucky, so 2012 as
Now I am a soil nut, we could not exist without soil, we are
totally dependent on soil for our food and clothing - don’t
think hydroponics will save us - most of the feed stock
comes from soil anyway.
Many of our environmental problems come
down to soil, one of the worst aspects of deforestation is
the destruction of soil, yet soil could hold enough carbon
to sequester manmade emissions
for fifty years,
giving us time to come up with alternative energy.
Soil is among the world’s most critical
resources yet we have a food supply system dominated by
major companies who pressure farmers to destroy their soil
to stay solvent.
Let’s face it farmers do not wake up each morning and
say ‘I think I will destroy another 400 hectares of soil, I
only did 250 yesterday so I must make a special effort
Rich or poor we all need soil.
Some forty years ago (yes I know I am
old) Australia suffered terrible dust storms losing millions
of tonnes of top soil. I realised that at some point in time
people would want to know how to regenerate top soil so I
started a series of experiments.
I bought every soil improver and clay breaker I could
find, gypsum, dolomite, sea weed extracts, sulphur based
clay breakers, saw dust, wood chips and so on plus I also
experimented with different ways of working the soil such as
contour ploughing and roto-cultivation, green manures etc.
Whatever else you may say about these experiments
they were certainly obsessive.
What did I find? There is simply no
magic powder you can sprinkle on claggy clay that will
convert it to beautiful loam.
Pity - it would be worth a fortune, but that is the
But over these last forty years I have
found that you can make soil, not instantaneously, but you
can make beautifully productive soil by following a
Now I anticipate some readers will want
a simple step by step procedure.
I do that right at the end but first I want to have a
bit of a yarn to show how the basic principles were
My relationship with soil goes back a
long way. I was
born and Hitler declared war and tried to starve and bomb us
Every bit of available land was brought into
production to grow food. To me, as a toddler people growing
food and bartering a sack of potatoes for a few cabbages was
the way the world worked.
One of my earliest lessons about soil
was the use of the use of the humble potato. A lot of waste
land, basically covered with weeds and overgrown was brought
into production. To get rid of all those weeds would have
been a horrendous job, made worse as there were no people to
do it - they were all busy making spitfires.
But potatoes are a hungry crop that could out-compete
the weeds and make the land productive for other crops later
on. A useful
lesson - look for ways of letting nature do the work.
That lesson was rammed home many years
later when in a burst of ignorant youth I roto-cultivated my
lawn to break up the heavy clay. When I finished it looked
beautiful, a nice fine tilth. But after the first heavy rain
it turned into concrete.
Another early learning experience I can
recall about soil is when we buried the remains of a chicken
in the lawn. You will not be surprised with all those
nutrients that the grass grew taller and greener than the
surrounding grass. But the grass continued to be taller and
greener for year after year well after all the nutrients had
It was some sixty five years later that
I began to understand the mystery of the dead chook.
that long ago I noticed the traditional fairy ring of
mushrooms on my lawn.
These sort of come and go as they feel like it, we
know how they work, a mushroom has a ring of ‘cannons’ ready
to fire out spores.
When the conditions are just right, and you need to
be mushroom to know when that is, they all fire off together
creating a ring of spores a meter of so away which makes the
fairy ring. But if you look at the grass inside the fairy
ring it is much longer and healthier than the surrounding
Now we know that the fungi are
particularly effective, far better than plants, at
extracting nutrients from the soil, there hyphae are very
fine so can exert very high pressures
and they exude enzymes which can dissolve rock
particles so the plants have an extra supply of food.
So the mystery of the dead chook was
the nutrients gave the grass a kick start, but they also
started a fungal colony which year after year helped feed
the grass, long after the nutrients had been distributed far
Soil is created by the millions of
creatures that live in the soil - the soil biology.
This is a complex business which scientists spend
But you do not need to know about every species in
the soil, rather you need to know how to farm the soil
biology, just like a farmer looks after his cows.
Soil biology has goodies and badies,
mycorrhizal fungi and worms are highly beneficial creating
the structure for the soil while nematodes can eat away the
roots, and cinnamon fungi and phylloxera create much damage.
The aim is to ‘farm’ the biology to
create conditions that encourage the beneficial biology
while discouraging the detrimental.
Plants, by photosynthesis, provide the
energy for soil biology. Some crops are beneficial for soil
regeneration but generally selecting plants specifically for
soil regeneration is faster and more effective.
The plants selected depend on the natural soil type
and the climate. I call these soil trees; they are grown
purely to create good soil.
Xiulan, my wife thinks I am mad, ‘you
grow rubbish trees’ she says.
But this is one of the few times I am right and she
is wrong, growing trees to improve soil may waste a bit of
land, but it makes the crops I do grow much more productive.
Selecting the appropriate soil tree is
an important job and it depends on the soil and the climate.
I live in an area which is subtropical,
(near what is left of Bundaberg after the floods) it is at
the same latitude as our major deserts and is dry for much
of the year, there is no regular rainfall we just get the
edges of extreme weather, mostly cyclones form the North in
summer but sometimes we get a winter storm from the South.
My soil is a seriously heavy clay
sticky, claggy and virtually unworkable when wet but like
concrete when dry.
These are pretty extreme conditions so I have to
search for a seriously tough plant that can thrive.
On the other hand I do not want it too ferocious so
it becomes a weed, there are plenty of weeds that thrive in
our conditions but they just get out of control.
most successful plant I have found to date is Senna Alata.
It can be grown from cuttings but seeds are probably
the easiest and it can reach maturity and flower within the
year. It can be
grown as an annual or as a permanent tree to act as a host
for the mycorrhizal fungi and worms.
It produces abundant foliage which I
use to feed the soil biology, and seems to thrive under all
conditions and is tough enough to out compete the weeds. It
is a legume, so harvests nitrogen and is efficient at
‘mining’ phosphorous, so it is a good source of two of the
big three N.P.K.
The root system is extremely tough and seems to have
no problem in penetrating my heavy clay.
Once I tried to grow it in polystyrene vegetables
boxes, - the roots just when right through.
The only snag I have found so far is
that it is does not handle frost which kills of the stem and
branches, but the roots seem to survive so next year the
plant just regrows, and it is such a fast grower that I do
not see that as a big problem.
I grow them in my wicking beds (they
make great stakes for beans and tomatoes) but also use them
in new system I am experimenting with which I call a sponge
boxes and beds are fine for smaller use but what about on a
This is where I see the sponge bed could be the answer.
There is no plastic sheet to provide a seal to
prevent the water leaking away. Instead I am creating a
highly absorbent layer deep in the soil.
It works like a baby’s nappy - holding onto the water
to maintain that uniform moisture essential for the
beneficial soil biology.
Moisture is the key to soil
know that most people think of wicking beds as a highly
efficient way of watering with virtually no loss to
evaporation or soaking beyond the root zone, but to me the
way they maintain a uniform moisture to aid the soil biology
is equally if not more important.
But why is moisture so important? To
answer this I must talk about the differences between
bacteria and fungi.
They are both decayers, taking their energy from the
organic material from plants, but they behave very
Bacteria are everywhere; they can live
almost anywhere on earth in the most extreme conditions form
sulphur emitting vent holes deep in the ocean to high up in
the atmosphere. They break down the organic material
emitting carbon dioxide while a certain amount of carbon
goes into their bodies.
But they are short lived and when they die their
bodies are eaten by yet more bacteria releasing more carbon
dioxide into the atmosphere.
The net result is that they are
actually reducing the level of carbon in the soil. They are
very small and do not move about and while they do release
some nutrients to the soil they do very little for the
structure of the soil.
Contrast this with fungi. They are even
more effective decomposers, attacking the hard material like
lignin (hard wood) which the bacteria tend to leave. This
forms humates, (or humus) complex organic chemicals which
are stable in the soil for years, both storing carbon and
aiding the structure of the soil.
Fungi are very long lived (in
appropriate conditions) and hold a significant amount of
carbon in their bodies, but they are very effective at
giving the soil its critical structure, breaking up the soil
and making it porous to hold more water and nutrients and
allow the plant roots to penetrate the soil. Plant roots
exude saccharides which feed the soil biology, so there is a
natural symbiotic relationship.
The mycorrhizal fungi form an even more
effective symbiotic relation with the plants attaching
directly to the roots, the fungi provide the plant with
moisture and nutrients which fungi are very effective at
harvesting (better then plants) while the plants provide the
fungi with sugars and energy.
Pretty neat deal!
The fungi are far more sensitive to
moisture levels only flourishing in a limited range of
moisture. To improve the soil we want to preferentially
encourage the fungi which we can do by maintaining the
Worms, the other great soil conditioner
also thrive in moist conditions.
However there are different types of worms which
fulfil different functions in soil regeneration.
The worms normally sold are compost worms which do a
brilliant job of breaking down organic matter however they
tend so stay in one spot.
Other varieties of worms are much
larger and stronger and are deep burrowing; they will come
to the surface to gather food then go back deep into the
soil. As they
travel they make the soil much more porous and play an
important part in soil regeneration.
The major advantage of wicking bed is
they maintain the soil continuously moist, not t wet not to
dry, just the right conditions for the beneficial soil
But how do we get the right biology
into the soil? I have many years experimenting and am now
developing the bio-pack.
I am using wicking beds with their consistent
moisture levels to grow what is in effect a complete eco
system of plants, mycorrhizal fungi, worms, micro nutrients
and the other components of soil biology.
These bio-packs are small enough to be shipped as an
inoculator to initiate the soil biology.
Just scratch out a little hole in the
ground, pop in a bio-pack, go and relax and let the biology
do the work. Life may be hard but is doesn’t have to be all
Soil can be created but is also being
destroyed by the release of carbon back to the atmosphere.
The organic materials in the soil are essentially long chain
molecules with carbon as the backbone, just like plastics.
But UV degradation and oxygen are powerful destroyers of
long chain molecules. If you have ever left a bit if plastic
out in the sunlight you will have seen how it first goes
brittle then cracks and finally disintegrates. It is the
same with organic molecules on the soil; they are
continuously being broken down by the deadly combination of
UV and oxygen.
But to make matters worse, the bacteria
are also breaking down the long chain molecules. The net
result is a loss of carbon back to the atmosphere.
On the other hand plants are continuously extracting
carbon from the atmosphere so carbon is continuously
cycling. If we
manage the system using plants, such as soil plants, to
continuously extract carbon from the atmosphere the carbon
content and soil quality will continue to increase year
However if we adopt inferior farming
practices (as farmers are often forced into) with a lower
carbon capture then carbon loss will exceed that gained so
the carbon level will decrease.
Clay, if left unattended, will always
revert back to its original form so it essential to keep the
soil biology fed and watered so they just keep on making the
It is a bit like pushing a wheel chair
up a hill. If you continue to push you will eventually get
to the top of the hill.
But if you let go it will roll back to where you
This cycling of carbon is the
fundamental administrative problem with using soil carbon as
a mechanism in fighting climate change.
The rules, decided over twenty years ago, say that
the carbon sequestered should be permanent, yet soil carbon
is continuously recycling.
It is totally the wrong way to look at the role soil
carbon plays in climate change.
It will never be a permanent solution to climate
change; we simply have to adopt new energy sources.
But that takes times, but soil carbon
is a cheap and immediately available technology which can
give us a window in time while we make that change.
On a global scale we could use soil carbon to
stabilise our atmospheric carbon for up to fifty years while
we make the needed energy changes, but we need to rethink
the role of soil carbon.
The current logic is just about as sensible as
jumping out of an aircraft with a perfectly good parachute
but not pulling the rip cord on the basis that the parachute
will be no use after you hit the ground.
Meanwhile people have their houses
washed away in the Bundaberg floods.
Wicking beds may be a very efficient
way of watering plants, but they need good soil. One of the
aims of developing the wicking bed was to create those moist
conditions for the soil biology, particularly the fungi,
which makes good soil.
So where do we start.
We could of course just go and buy some soil.
But here is the snag.
Processed soils are deliberately sterilised so any
harmful bacteria has been killed, but that also kills of the
OK so you can buy top soil. Sometimes
you see ‘mountain soil’ advertised, giving the impression
that the soil is imported from the rich mountains of Nepal
at amazing expense. Now what often happens in reality is
that the company goes around building sites collecting the
spare top soil, they take it back to their yard and pile up
into a mountain then sell this as ‘mountain’ soil
So generally I prefer to use local soil
and improve this.
At least the soil will contain local soil biology
which is well adapted.
The three basic aspects of soil are the
physical, e.g. particle size and distribution, the soil
chemistry, what nutrients (or harmful chemicals) may be in
the soil and the soil biology.
see how we can improve an existing soil – starting with the
There is a very simple experiment which is really quite fun.
Just take a sample of the soil (about a cupful) and
put into a glass container.
Fill with water and add a little detergent.
Break up the soil until it is a uniformly mixed
clay soils this can be a bit of work.
Then just let the particle settle and watch from time
If you have not broken up the lumps of
clay properly they will fall straight to the bottom.
Don’t worry just mix them up and start again, maybe
squeezing with your fingers until all the lumps have been
The larger sand particles will fall out
first. This may occur in a few minutes. It always surprised
me that a soil which looks to be totally clay with fine
particles may still contain significant sand particles.
Sand can also contain significant amount of fines.
This will form a uniform layer at the
bottom of the container.
Next the finer particles, which may be classified by
a soil scientist as silts, will start to drop out.
This will take a few hours.
Finally the very fine clay particles will settle out.
It could take several days or weeks for these very fine
particles to settle out and the water is clear.
You may also find bit of organic
material floating on the surface.
It is pretty obvious what the
distribution of particles in your soil is like just by
looking at the various layers which are usually pretty
clear, but if you like you can drain out the water and
examine the various layers using a magnifying glass or
(You can buy quite cheaply little magnifying cameras that
fit onto your computer. I bought mine on EBay and it is
Having found out about the structure of
your soil it is time to start rectification.
If your soil is predominantly sandy you
are lucky as this is very good for wicking beds.
Normally sandy soils are not considered good as they
hold little water or nutrients.
The larger particle size means there is less area for
the nutrients to bond to.
But sand is still a pretty good wicking
medium, we don’t have to worry about the water draining away
and using the ‘compost pipe’ the plants are fed a compost
tea which provides lots of nutrients.
If the sand level is extreme with no
fines then adding a little clay may be beneficial.
Clay particles are so small that they have a larger
surface area that the nutrients attach to.
A heavy clay soil is not such good news
but still solvable. You need to mix in a combination of
dolomite or gypsum and sand.
Don’t be mean with the sand, too little will just
make the clay like concrete without breaking up the clay.
Add at least 20% sand.
When the clay is wet if is very
difficult to mix with the sand and dolomite, it just forms
frustrating lumps. Not much you can do about this other then
let the clay dry out when the clumps can be broken up
I have to admit that breaking up lumps of clay is not my
ideal way of spending a Sunday afternoon - so I cheat.
When I have got the big lumps broken down I will fill
my wicking box to within about 50mm of the top, then add a
50mm layer of vermicast (worm casting) into which I can put
my plants. The
worms and soil biology can then take over the job from where
I left off.
Now you have a base soil you need to start working in the
additives to give the soil body and tilth.
This will depend on what is available locally.
Vermicast is excellent as is compost or whatever organic
material is available.
I use tonnes of mill mud, a by-product form the sugar
mill near where I live, but it is really up to you to find a
local source of organic material.
really needs to be a balance between brown and green
material. Unfortunately much compost is what I call brown,
food scraps may contain a little green material but are
still largely brown.
This is where the soil trees come in - providing a
supply of green leafy material.
In principle I prefer direct in soil
composting but sometimes pre-composting is needed.
Next we have to consider the chemical
requirements. This is a mature area of science with many
references, in particular
Garden talk by Colin Campbell and The new Organic
gardener by Tim Marshall.
Colin’s book has some very useful tips on recognising
deficiencies by inspecting the plants.
If you are going to use a lot of
undecomposed organic material you will need to add extra
nitrogen as decomposition takes out a lot of nitrogen.
I use chicken pellets and blood and bone.
But a word of warning, with
conventional growing there is always a loss of nutrients by
does not normally happen in a wicking bed unless you
deliberately flush. This means that it is very easy to over
know you can get all sorts of test done on soils but the
easiest way is let your plants tell you. If you are finding
they are growing too fast, such as lettuce bolting
prematurely or radish and carrots splitting then you have
too much fertiliser, particularly nitrogen.
Generally the big three (N,P,K) are
readily available so be careful how much you add.
I prefer organic fertilisers as they are slow
release, but I am quite happy about adding extra potassium
even as a chemical.
Now comes the minor and trace elements
and this is where the controversy starts.
Soil scientists generally talk about primary,
secondary and trace elements.
Plants must have some of these but the amounts are
very small. That is to make the plants healthy.
But we are animals and the amount of
these minor and trace elements we need is much higher than
plants, the level of these elements in our bodies it
typically ten times that found in plants. This is also
important for the soil biology, worm farmers report that
feeding the worms extra minerals improves their health.
And this is where I must digress.
When Bill Mollison first launched
permaculture on the world it created quite a stir.
His arguments about the weaknesses of modern
mono-culture agriculture seemed so powerful that I was
hooked and decided I would have a go at self-sufficiency.
Now that was a learning experience.
I learned that it is relatively easy to plant the
seeds and grow a good crop; it is a totally different thing
to plants seeds every couple of weeks or so and get a
continuous supply of food.
First there is the human fallibility of
not planting on a regular basis, now that is my problem -but
then there is the issue of natural variability and the
weather. Let me tell you what about the real world and
I can put in a quarter of a packet of lettuce and the
germination will be pretty poor so I know that I am not
going to get a good enough crop.
So I will race out and plant a full packet to allow
for losses. Now as far as I can see I have done everything
exactly the same as last time but this time I will have
virtually 100% germination so I think I am going to be
flooded with lettuce.
Now I live near Bundaberg and we were
hit by a mind blowing amount of water.
We had 820mm of rain in 3 days.
We had 300mm fall on the Sunday night (when North
Bundaberg was washed away).
I reckon that we had 100mm fall in about three hours;
I thought I would go outside with my torch to see whether
the drainage systems I put in after the last floods were
coping. The force of the rain and wind was so great I turned
straight around and went back to bed. This was no place for
humans to be outside.
In the morning I inspected, the
drainage systems I put in after the 2011 floods went
straight under my house. These had done an excellent job,
just some wind-blown rain but no flooding. But my bumper
crop of lettuces was totally pummelled into the ground.
I think back to the war time, when we
weren’t playing at self-sufficiency it was for real. How did
we manage? Well we did not have a continuous supply of fresh
vegetables, we grew crops which could be stored, we had
sacks of potatoes in the cellar, mum pickled what seemed
like sixty million jars of cabbage, made jam and preserves.
I am happy to let nature takes its course and just see what
grows well. The
answer on my block is pumpkins, I don’t think I have every
planted or bought pumpkins, many years ago someone may have
given me a pumpkin and the waste went onto the compost.
Now every year we have this forest of self-set
pumpkins that invade our property - enough to feed us for a
year. Yes it
would be perfectly possible to be self-sufficient but in my
case that would mean periods of living of pumpkins and that
does not necessarily mean a healthy diet.
Now you have heard my views on our food
distribution system, and it is just a fact that plants are
bred for appearance and shelf life rather than taste or
nutritional value. But give them a go; they have been
remarkably effective in bringing food from all over the
world to the local shop at remarkably low prices, (even if
that means squeezing the farmer on price).
So what do we do?
Well I am relatively lucky, I live in a rural area
with a local market where I can buy food grown locally and
even our supermarket (run by a local guy) buys in local
produce. So I
grow what I can and buy locally what I cannot.
But I want to make sure that the food I grow provides
the phytochemicals my body needs.
Phytochemicals are the complex
chemicals produced by plants some of which are known to
science while many are not. But as long as we eat some food
grown in soil with a high concentration of the micro
elements we need then there is a fair bet they are providing
all the supplementary food we need.
I find it difficult to argue the case,
on either economic or practical reasons, for trying to
bought in foods with home grown.
But I strongly argue that you can grow high nutrient
rich plants, full of phytochemicals, to provide the
necessary minerals and speciality chemicals (vitamins etc.)
needed to health.
This is an infinitely better approach than stuffing
yourself full of expensive vitamin pills.
Now you may ask if science hasn’t even
identified all these phytochemicals then how can I say that
these are important for health?
Well no one can be sure, but life is about managing
risks. On the
one hand I can eat fatty meat and greasy chips or I can eat
a combination of fresh vegetables I buy in, plus some I grow
some myself in soil with a high micro nutrient load.
I look upon these home grown vegetables
as a supplement - much better than eating tonnes of vitamin
Am I right?
Well to help you decide can I tell you
a little story from my studies into anthropology. It is a
little known fact that some hundred thousand years ago there
were two breeds of human like creatures on the earth.
The first group were not particularly
intelligent and just went about their business of surviving
in the way that seemed best to them at the time and
basically having a good time. But at least they were action
orientated and got things done. These were the sort of guys
that would pull the rip cord on the parachute, even if they
had not worked out what to do with the parachute when the
landed on the ground.
The second group were super
intelligent; a bunch of Fourier’s, Newton’s and Einstein’s
who spent much of their days discussing issues of the
greatest significance. Great debates of the highest
complexity but they only took action were they were totally
sure with total scientific proof. (Non rip cord pullers).
Now one day they came around to discussing sex.
They came to the conclusion that they did not have a
proper understanding of sex and that as DNA was not going to
be discovered for another hundred thousand years that they
should wait until the discovery before having any more sex.
WUSP was there motto, wait until scientifically proven.
Despite their super intelligence they
became extinct while the other mob prospered.
But the ‘smarties’ did not go quite extinct.
A few of the lads thought that they should conduct
some scientific experiments on sex, purely for knowledge of
So they high tailed it over to the
other camp, where things had been quite active.
After a good meal of kangaroo steak George asked
Mavis if she fancied a bit of hanky-panky. Now Mavis thought
well washing up won’t be invented for a hundred thousand
years, so why not, so off to the bushes they went to ensure
the propagation of the species.
Now the lads from the intellectual camp
met up with Mavis’s younger sister and cousin and started to
chat them up - as young lads do.
Now these young lasses had not had any hanky-panky
for some time and hadn’t been brain washed into the benefits
of abstinence by the yet to be invented religious orders, so
they told the lads to stop talking, grabbed them by their
kangaroo shirts collars and took them off to the bushes.
And so their genes survived which is why we have
people saying we should wait until the science had been
confirmed before taking action on climate change (by for
example exploiting the benefits of soil carbon).
The solution to that is to incarcerate them all in
North Bundaberg which was wiped out in the last floods.
So we may not be sure that eating at
least some vegetables grown in soil rich in micro-nutrients
is the proven way to health but it is certainly the best
show in town.
But here lies the snag.
It is easy to add the micro-nutrients to the soil,
but these were made by grinding up rocks which are
insoluble. Just adding micro-nutrients does not do much
good, the plants cannot access them.
This is one of the many roles of soil biology.
Biology is what gives soil its
structure; it creates aggregates and fine passages which
enable the roots to penetrate the ground and the soil to
hold much more water.
Soil biology is what releases the
nutrients which may be locked up as insoluble minerals into
the complex soluble chemicals which the plants can take up.
Whether you are starting with a clay or
sandy soil the soil biology can convert it to open quality
soil with a good tilth.
It is as the heart of making us healthy by eating
You can see I get a bit steamed up
about soil biology.
what do you need to do to get a good soil biology?
Well just take what I am about to say as a bit of a
shock treatment, forget about your plants, whether they have
enough water and food, just be totally obsessive about your
soil and its biology.
(I told you I was a soil nut). But this is not as
daft and extreme as it sounds. If you look after the soil
biology the plants will automatically grow well.
Now do not think for one minute that
you can just go and buy one of my bio-packs and you will end
up with beautifully rich soil, because you won’t. Putting a
bio-pack into your soil is a bit like having a baby dumped
on your door step.
If you just leave it there it will simply die - you
have to look after it by feeding and watering it (and let it
with a wicking bed is easy.
In a wicking box it is convenient to use a sight
glass, (which also makes them easy to drain).
In the larger wicking bed, it is not so easy to put a
sight glass, so even if you use a compost pipe it is still a
good idea to have a pipe so you can see the water level. The
only decision is whether to keep the water reservoir topped
up (shallow cycle) or to let the water level drop until
almost empty then refill (deep cycle).
I prefer the deep cycle for two
reasons. First the deep filling and emptying cycle is
actually sucking and expelling air - like breathing.
Secondly I now fill my wicking bed completely with
soil and do not use a separate reservoir.
The plants can then use the full depth of the soil,
the roots do not mind an occasional saturation you get with
the deep cycle but with a shallow cycle they will not live
in the continuously wet soil.
Soil biology cannot photosynthesise (generally, algae and
some specialist organism can).
They are totally dependent on the plant for the
plants for energy. Mycorrhizal fungi gets its energy
directly from the plants but the rest of the soil biology
has to chump up dead plants.
my first generation wicking beds I had a plastic water pipe
feeding the bottom of the bed, in the second generation I
added a worm bed, typically a plastic bucket with holes in
the bottom, filled with organic waste and worms. Then I
thought this is silly I am wasting a lot of space in the bed
and the worms are a bit restricted and may not work through
the bed properly, so I combined the pipe and the worm bed
It’s dead simple.
When I make a bed I just put a pipe into the box,
fill the box with soil and the compost pipe with (yes you
have guessed it) compost.
I pull out the plastic pipe making sure the compost
is pushed down.
Next put in the bio-pack, then the seeds, water and I am
away. It is
really a question of minutes to set up a box.
is a relatively new method.
A hole is formed in the soil using an old flower pot
or a pipe, this is then removed and the hole filled with
I have had no problem with the water
pipe clogging up, but I have a variety of weapons (see pic)
to clear it out or make a new one if needed. I am also using
these tools to make compost pipes in existing beds.
maintain the box I water through the compost pipe, this
flushes out a compost tea which flows to the bottom of the
box then wicks up.
I can add fertiliser and the trace elements to the
Using chicken pellets and blood and bone help the compost to
I do pre-compost some of my rubbish but
I also like to add fresh green material to my compost pipe.
Adding further compost is where wicking
bed users seem to have a variety of approaches.
Some like to use it as a mulch around the plants.
I am sure this is good but I have a slightly
Surface mulch is broken down both by UV light and bacteria
whereas my approach is to say that all that light that is
falling on the mulch can be used to grow more plants, I like
companion planting putting new plants in among the others as
a space appears.
I could argue the technology for doing
that but the real reason is that I am just a messy person
and just like having a rolling stream of plants filling up
all available space – it just suits my personality. Many
people like plants in nice straight rows, if you are one of
those I salute you and please come and tidy up my house
which is a mess. (Xiulan is in China so I can get away with
the mess, as the saying goes while Xiulan is away Colin
messes up, I think the original was more to do with cats and
Have I had problems? Well yes some of
my early beds which used mainly clay with no sand have
become quite hard but that was after about five years. I
simply aerated by pushing in a fork and levering back until
the soil cracked.
I did not dig or disturb the soil and it worked fine.
I will just have to wait another five years to see
how the current system using more sand, dolomite and the
bio-pack work out over time.
I will just mention that in my sponge
bed I am putting the cutting from my senna trees into
trenches so it goes
into rather than
onto the soil, but these are still experimental and the
topic of another article.
So at last here is the summary
Check the available soil for sand and
If the soil is predominantly sandy then
you can use 75% soil but if clay is available 50% sand with
25% clay may give more body to the soil.
If the soil is predominantly clay then
use 50% clay 20% sand 5% dolomite or gypsum
Add 20% vermicast or compost
Add 5% organic fertiliser chicken
pellets and blood and bone
Build the compost pipe into bed and
fill with compost (insert dummy pipe, pack soil around the
outside, carefully pull out dummy pipe).
Create small holes every metre and bury
bio-pack level with surface
Plant as you see fit
Ensure compost pipe is regularly filled
with fresh compost and add trace elements as needed.
are my latest passion to provide a broad spectrum soil
biology. I am
trying to create a miniature self-contained eco-system. I am
growing plants which have been inoculated with mycorrhizal
fungi so it is properly established before shipping.
The plant I have selected as a host or mother is gotu
kola. This is a
herb with reputed major health benefits, is tough and fast
request I will also incorporate some senna alata seed.
I should point out that these only germinate when the
soil is warm.
The bio-pack is heavily loaded with a
mixture of both compost and burrowing worm eggs and trace
elements, certainly sufficient to start a wicking bed off.
You should probably add further trace elements
can supply if needed.
At this moment I would describe the
systems as pre-commercial. To be honest I have no idea what
the demand for bio-packs will be, this is the first time I
have announced them. For the moment I have set up a couple
of wicking beds and will supply straight from the bed on
receipt of request. The senna are setting seeds as I write
but these need to be dried out ready for the spring.
Currently I am looking a price of $25
per bio-pack (plus p&p) which will inoculate a meter square.
If there is the demand I will organise larger scale
production by a commercial organisation. In view of the
length of time it takes to establish a mini eco-system in a
wicking bed I doubt if they will do it cheaper than I can.
You should contact me directly if you