For most gardens and households, there's generally a continuous supply of material available
for the compost throughout the year.
There are of course seasonal variations, or periods when the gardens are cleared, when
there might a lot more material available, but the supply tends to be reasonably consistent.
And we usually set up composting system based around this steady supply, which can normally
handle some larger quantities of material as it becomes available.
But sometimes, so much material comes along all at once that it's hard to accommodate,
especially if there's limited space or capacity.
These bursts of material can be difficult to manage and can often overwhelm whatever
composting systems we've set up.
These larger quantities of occasional compost material, I tend to call fertility bombs.
Years ago a friend of mine described to me the idea of a money bomb, when you get a larger
clump of money suddenly, in addition to your regular income.
An inheritance, tax return, payment for a big job, or the sale of something valuable,
these are all what can be described as a money bomb, in addition to our weekly or monthly
pay check.
I’ve always liked this idea of a money bomb, and have adapted the name to fertility bomb,
to describe when I receive large quantities of fertility or organic matter for composting.
I've gotten material from the local bakery, from restaurant kitchens, and a diverse range
of other material, where people are looking for a useful place to put this stuff, instead
of sending it to the dump.
A lot of this material I can incorporate into my current systems, which are quite big, although
they do cause some issues.
But I’ve also received huge loads of pulp from the pressing of apple juice, and huge
piles of rotting apples, all of which needed me to do something completely different.
I manage a small community composting facility, which I called the no-rules compost, and it
can absorb a fair amount of material at any one time.
I do need to be mindful though, to be observant of what is being added and to mixing in other
materials as needed, and I’ve learned over the years to always have a store dry material
just in case.
But these larger quantities of material can fill up the bin quite quickly, which is an
issue with the system that I have.
When the first compost bin fills up, I need to turn it, to empty it, but before I can
do that I needed to turn all of the other piles to make room for the first one to be
emptied.
This was a lot of additional work, and adding lots of extra material is not ideal for the
method that I have developed for general everyday composting, although it was manageable most
of the time.
Things changed quite a bit when friends started to expand their small apple juice pressing
business.
They suddenly had loads of apple pulp that they needed to get rid of in some way, and
I wanted to help them out, and to take advantage of this new source of fertility.
But this was way too much material from my compost system.
I also didn’t have enough other material to mixing with it in order to be able to create
separate batch compost piles.
I just wasn’t prepared for this volume of wet material, and I had to scramble to figure
out what to do with it all.
I added some of it to my usual composting system, but I also decided to spread some
of it as a mulch on part of my No-Dig Garden.
And I spread more of it over the part of soil in my Simple Garden, which was then covered
with ground cover fabric.
These were both experiments in sheet composting, and I wasn’t sure how they would work out.
The experiment of using apple pulp as a sheet mulch in the No-Dig Garden didn’t work out
very well.
Perhaps the layer was too thick, but it was also a very wet and cold winter, and the layer
remained sloppy and seemed to become anaerobic.
But by the spring the worms seemed to be working through a lot of the material, which was a
good sign.
In some of the sections of this garden, I decided to scrape the remains of the pulp
off of the surface of the soil in the spring, and to add it to my compost systems, but in
other parts fo the garden I decided continue with this experiment.
In one section I covered the remains of the apple pulp with a layer of compost, and a
while later I transplanted in cauliflower and calabrese plants into this bed.
In the places that had had apple pulp underneath, these plants did significantly worse, especially
at the start of the season, although later on the growth improved.
I’m not sure if this was due to the anaerobic conditions, or the type of active biology
that was involved, the acidity of the material or some other factor, but I'd hesitate in
doing this again.
If I did, I’d try to mix in compost in with the pulp material in, rather than leaving
it as a homogenous layer, or I'd at least cover it with some other material right away.
This same messy material under the ground cover fabric in Simple Garden did much better.
The fabric definitely hid the mess, and perhaps created better conditions for the worms and
other soil organisms to work through the apple pulp during the winter months
The squash that I grew in this section of the garden were also planted later in the
spring than the brassicas had been, which would have allowed more time for things to
settle down.
Squash plants are also notorious for being able to grow very well in areas of active
decomposition, and are quite happy to grow directly on top of a compost pile, and seemed
to be a much better crop for this type of sheet composting.
That same autumn I had added loads of spoiled apples that have been damaged in a big storm,
and couldn't be pressed for apple juice.
This huge long pile of apples was quite wet and slushy under the fabric for most of the
winter but by the spring there was lots of worm activity.
throughout it.
By mid summer there is only a crust of apple skins and cores remaining and 16 months later
there is not a trace of this massive pile of apples.
And I ended up with a really good crop of squash out of it, the best from all of the
gardens in that last season.
I’m not sure about the effect of the acidity of such a large volume of material but I think
it’s probably less of an issue here with the calcareous soil that we’re working with,
with its high pH.
No doubt adding such a large quantity of any material will mess around with the soil fertility
in some way, and this is something that I need to take into consideration, and at very
least in the future I should mix the apples in with some other material.
Based on the limited experience so far, my preferred method is to sheet compost fertility
bombs under a layer of ground cover fabric, and then to grow squash or pumpkin plants
over top of it.
It is amazing how much material can be added using this sheet composting method, especially
with the really messy stuff.
Of course this method is not without its issues, and I’ve had several instances of rats making
a home for themselves under the fabric, and then I’ve had dogs ripping up the fabric
trying to get at the rats, but then again, I’ve had the same kind of problems with
my other composting piles.
Another possible method I’ve tried a few times, but would like to do a lot more experimentation
with, is trench composting, and this would involve setting aside specific areas, planning
for what crops will go in afterwards, and ideally digging the trenches in advance, especially
if I’m anticipating a large volume of material all at once.
The use of animals to manage the fertility bombs is another possibility and is often
suggested by other people.
Pigs are an obvious possibility here, which I've never had, but I have had hens at times.
The problem is that I would have to keep them alive and well fed when the fertility bombs
are not available, so that they are ready and able to help when I do get this extra
load of fertility.
Keeping pigs so that they can eat the apple pulp for only a short period of the year,
just doesn’t make a lot of sense to me.
I think animals are more suitable as a way to process relatively consistent supplies
of food waste and other materials, as they need to eat regularly.
The other option is to make large batch compost piles, but this means I have to have lots
of material ready and waiting to mix in with whatever stuff I think I might receive.
But I think that dedicated large batch compost piles are perhaps the best option in my context,
after sheet composting.
I’ve found that a lot of the large loads of materials I've received in the past has
been unexpected, and I’ve had to process it at the last minute so I ended up scrambling
and I've had to make some quick decisions.
I think the key to all of this is being as ready as I can be, to have a number of different
options for when material does arrive.
Having extra space definitely helps, especially with large volumes of potentially really messy
material that I don’t want to have to move again, or process any more.
I’m already starting to plan for apple juice season next autumn, and I really hope that
it's a good season for my friends.
I will definitely be sheet composting some of this apple pulp, as I have in the past,
but I’m also planning to stockpile large quantities of dry, high carbon material and
other organic matter to mix in with the apple pulp, to create large dedicated compost piles.
I’m planning to be ready for this sudden abundance of fertility, and for any other
fertility bombs that get thrown at my gardens.