Living a Sustainable Allotment Life

This post has been updated for 2020

This video is about our allotment related sustainability efforts.  These are directed primarily at reducing our: fresh water use, carbon footprint, consumption of single use plastic and exposure to toxins.  We are also trying to build top soil, encourage beneficial birds and insects, increase our food quality, save money and have a lot of fun.  Some of the money we save will be used to buy carbon off-sets for the things we can’t change on our own (we recognise the problems with carbon offsets, but it’s the only tool we have).

Allotment Inputs and Outputs

Our main inputs to the allotment are waste products: various manures, leaves, wood chips, seaweed (from the beach and purchased too) and – my favorite – spent mushroom compost.  We also recycle allotment waste into compost, but that’s not an input.  Of course seeds are an important sustainability input , but they’re not the subject of this video.

Ideally the only input we’d need, other than waste products, would be the sun and the rain.  Unfortunately though we live in one of the dryest places in the country and as a result we don’t get anywhere near enough rain to achieve anywhere near optimum harvest levels, we accept that, but we do like to achieve good harvest levels so we add tap water too.  Fortunately that tap water has a hugely positive impact on the overall sustainability of our efforts, it’s not a negative input (see later).

We also add a lot of personal effort and we do it with care and love.  That’s important because we are not reckless with our efforts: we don’t over-work, over-water, use inorganic fertilisers or pesticides and we try hard to nurture the ecology of the soil and the broader environment.

Finally we get the outputs and for Debbie, Jennie, Jon, Robin and I that’s a lot of fun and companionship as well as improved health from the physical activity, the fresh air and the high quality food.  Also if we do it right – and we do – each year the amount of soil increases, the soil quality improves and the ecology of the allotment gets richer.

Most important from a sustainability standpoint is that we grow a lot of food, so lets dig into that.

Growing a lot of food

Our primary objective is to be self-sufficient in vegetables all year round and seasonal fruit, that’s the original purpose of an allotment of course.  We also extend the season for fruit by dehydrating, freezing and making preserves.  The process of dehydrating and freezing is – so far as is practical – fuelled by our solar panels.

There are several ways to look at how much we harvest, but my favourites are to look at the value, about £10,000 and the number of meals, about 10,000 too.  I get those figures by counting the number of the 2 litre containers that we fill, about 4,000 a year, during 100+ harvests, plus bulk harvests of fruit, potatoes, beets etc.  That’s a lot of harvests and a lot of packaging that we eliminate.  The containers get used well over a hundred times and then eventually get fully recycled.

Debbie, Jennie, Jon, Robin, Tessa, Ollie and I eat about half of this food: the rest gets gifted to extended family, friends, neighbours and fellow allotmenteers.  We try hard to ensure that the food we gift is grown in our kitchen garden, because our allotment site is banning gifting outside the family, but gifting is important for several reasons.

Why gift so much food?

While it’s possible to be self-sufficient without growing a surplus, it’s extrordinarily difficult.  In February for example we have just enough – wonderful – lettuce and then two months later we have much too much and no summer crops to replace it with, so it’s gift or compost.  Similarly in September we are overflowing with kale but by February we are just scraping by.  Finally it’s essential to grow too much to offset the risk of failures: in 2018 for example we lost a third of our spring salad beds to mildew, in 2019 we lost half of our Christmas potatoes to blight, all of our August sowing to contaminated compost and probably a quarter of our brassicas to cabbage root fly.

Resiliance to the ravages of pests and disease and the cycle of sufficiency and surplus applies to almost everything that we grow and we grow 150 varieties of fruit and veg each year.  Storing the surplus is only a partial solution and often involves destroying what makes the food so wonderful in the first place.  A dehydrated apple for example, or a frozen cauliflower or carrot is no substitute for the glory of the same food fresh from the plot.  So whereever possible we eat fresh and we grow enough to ensure a very rich and diverse diet all through the year, if we are lucky the result is surplus.

A lot of people we know compost their surplus, but we are fortunate that we have so many wonderful people to share that surplus with, a community of passionate fruit and veg lovers who relish fresh ‘organic’ food as much as we do.  Friends and family who return the gift of veg in a myriad of ways: the smile on their faces, their improved health, the money they save and spend on their kids, their own surpluses they sometimes gift back to us, the free drinks they buy us, or the restaurant meals, the help on the allotment and the glow that comes from doing a good deed.

It turns out though that a surplus takes on a whole new aspect when examined from a sustainability perspective. Growing our own food requires about 80% of the inputs to the allotment.  The surplus has a much lower – 20% – marginal cost of input (water, manures, plastic etc) but it delivers 50% of the sustainability benefits (water savings, reduced carbon footprint) so it’s a vital part of our sustainability efforts!

Sometimes on a lovely sunny day I think that I’d like to grow even more food, and it would certainly be possible, and good for the planet, but there are a few constraints:  the most important is that achieving optimal yields requires more effort than I have the energy for given the limited time I’m able to work (due to health constraints) and more water than is available (due to the councils cost constraints) so we stick with doing just what’s needed to be self-sufficient, it’s a reasonable balance.

So the bottom line is that growing enough food to be self-suffient means you will have a surplus, it’s just the nature of things.  The trick is to make the best use of the surplus to maximise sustainability and good in the world.

Toxin free food

Organic is a problematic label to attach to allotment grown food.  We don’t know what happened on our plots before we arrived, or if we do, we’d rather not think about it.  We don’t source organic horse manure and I don’t think it’s possible to buy truly organic spent mushroom compost.  We can’t practically comply with a myriad of other regulations required to attach the official organic designation.

What we can say though is that herbicides, pesticides and inorganic fertilisers don’t go anywhere near our food, except in very specific circumstances (we spray apple trees twice for Codling Moth for example).  That contrasts sharply with most commercially grown fruit and veg that can be sprayed dozens of times in it’s life.

Taking these steps doesn’t just benefit the food directly, because many inorganic fertilisers and insecticides and herbicides damage the life of the soil, they disrupt critical natural cycles or throw processes out of balance. Ultimately an unhealthy soil doesn’t grow optimally healthy plants.

The bottom line is that we take most, if not all, of the practical steps to reduce our exposure to toxic chemicals on, or in, our food.

Water sustainability

We capture as much rainfall as we can, but we also depend on tap water for the allotment in spring and summer.  It’s natural to focus on the tap water usage as an input, a sustainability problem to be reduced, but that would be a mistake.

The way that we grow food on the allotment is massively more water efficient than commercial food production, that we would oherwise depend on, for a whole host of reasons. Some of the most important are detailed below:

1. Our soil quality is much higher, it holds much more water because it’s mulched and rich in organic matter
2. We grow much more intensively, sometimes harvesting more than an order of magnitude more food per square meter than land-rich, labour-poor, farmers
3. We plant much more carefully, pre-watering holes to encourage deep rooting of young plants and then by carefully direct watering when establishing the plants to further encourage deep roots
4. When watering established plants we use all manner of tricks to try and direct water to the root zone
5. We water by hand and with careful attention to how dry the soil is: so just enough water, in the right place and at the right time of day
6. We harvest in a cut and come again fashion, a little each week, for many months, which yields vastly more than harvesting once and then waiting months for another crop to grow
7. We try to eat the whole plant, for example: we eat the sprouts, the sprout leaves and the sprout florrets, we eat the beetroot leaves and roots, we eat the radish leaves and roots
8. We never leave the soil bare, when one harvest finishes, another – module grown – plant takes it’s place, even over winter. Winter rain doesn’t just flow into the sea, first it nourishes all of the plants on our plots.
9. We capture rain from every structure
10. All food is washed on the allotment using tap water, that water is then used to water the plot, no soil leaves the allotment (lugging all of that tap water to the plot for 6 months of the year is a major headache though)

Many of these techniques are wholly impractical for the commecial grower, but pracical for small scale, labour rich allotmenteers.  The end result is that for every litre of water that we use on the allotment, we save 20 litres of water that would have to be used by a commercial grower.  That’s incredible and it makes efforts to try and reduce water usage on the allotment still further counter-productive. Although if we were squandering water on the allotment using sprinklers all day long it would be a different story.

To make this more concrete, in order to grow the quality and quantity of food that we grow a commercial grower would use 1,318 cubic metres of water according to data from waterfootprint.org, which provides water usage/kg for fruit, vegetables and roots. What we grow is skewed towards leafy greens, which are the most water hungry commercial crops, so this figure is likely to be conservative.

In order to grow our 10,000 meals of fruit and veg we only use 33 cubic meters of water across the three allotments in a typical year, that’s just 2.5% of what a commercial grower would use, of that 33 cubic metres we capture about 27 in our rainwater harvesting system.   It’s worth noting that small scale organic market gardeners using drip irrigation have similar levels of water efficiency to us, unfortunately a tiny fraction of food is available from these growers.

That 6 cubic metres of tap water has a value of about £12, but it enables a harvest value of £10,000 there’s no better financial or sustainability investment on the planet!  Fortunately as a country we’ve generally moved beyond our own selfish interests now and are taking our global sustainability responsibilities seriously, we do the same.

It’s also worth noting that although we might be more efficient in water usage than the typical allotment, we are almost certainly less efficient than the best.  On average though allotments will always be much more water efficient than commercial growers and so they are always a big sustainability win.  Managing and watering an allotment as described in this post is to be celebrated.

Plastic usage

Commercial – supermarket – food uses an incredible amount of single use, non-recycleable packing, much of it plastic with a little cardboard.  We on the other hand use only reusable (BPA free) plastic containers and, to date, we have had very few of them break, we estimate that they are good for hundreds of uses, after which – because they are a high quality plastic – they are fully recycled.

Food Miles

Look around any supermarket fruit and vegetable section and you will  be amazed to see that almost all of the food has travelled half way around the world.  Worse yet, take a look at a local farm shop and you will be stunned to see that surprisingly little of it has been grown on the farm or sourced from local farms, it’s foreign too.  In contrast all of the vegetables and seasonal food that we eat is grown on the allotment and eaten by people who live within 3 miles of it.  In addition, aside from a few miles in the car – to harvest – most travel is by foot or bike.  Fruit and veg deliveries are all on foot.   The bottom line is that our 10,000 meals have almost zero associated food miles.

It’s also worth taking a look at the miles travelled by our inputs.  Manures, wood chips and spent mushroom compost all come from local farms or gardens, less than 10 miles away and are delivered in bulk once or twice a year.  The actual food miles are included in the following section on carbon footprint.

Carbon Footprint of the allotment

As already mentioned the carbon footprint associated with the allotment plots is very low.  The inputs are almost all locally sourced waste products, the packaging is reused hundreds of times and completely recycled, the polytunnel steel frame will last for 20+ years and be fully recycled.  That leaves only the plastic for the polytunnel, cold-frames and module trays and other miscellaneous items that I confidently estimate at less than and average of 0.1 tons of co2/year, (see https://www.youtube.com/watch?v=qI7VGvbUj2g for more details on this).

Now we get onto the good stuff.

The chart shows the co2 for different types of diet.  We feed between 10 and 30 people depending on the time of year and they are a mix of: average, no-beef, vegetarian and vegan.  I’ve taken the average as vegetarian and the average number of people that we feed as 15.  From the chart I can see that a typical vegetarian’s co2 footprint for fruit and vegetables is 0.5 tons and we feed an average of 15 people, so if they ate commercially grown fruit and veg it would have a carbon footprint of 7.5 tons of co2.

All the veg and seasonal fruit that Debbie and I eat is from the allotment (and we eat a lot of fruit and veg) but the other 13 people don’t exclusively eat allotment fruit and veg, so accounting for that I calculate that the carbon free food that we grow for them reduces their carbon footprint by at least 3.38 tons of co2.  We need to reduce that by 0.1 tons, because that’s what the allotment’s plastic etc creates, which gives us 3.28 tons saved/year.

That’s not that much of a saving unfortunately, taking a single international flight would release that much co2.  Fortunately, Debbie and I don’t fly, so it’s actually quite a big deal for us, in fact it’s enough to offset the co2 footprint of the rest of the food that we buy.  That means all of our food is carbon zero with 0.28 cubic metres of co2 to spare!  That 0.28 tons conveniently covers the carbon footprint of the allotment specific transport.

So the bottom line is that thanks to the allotments all of the food that we consume is carbon neutral.

Financial self-sufficiency

We are most definitely not self-sufficient in food.  Although we grow all of our own vegetables and seasonal fruit, we buy a lot of fruit out of season and we also buy oats, oils, nuts, dairy, flour, meat and much more.  Our eggs are gifted to us by friends who have back yard hens and our lamb and beef comes from animals raised on marginal land, but we still have to buy it.

However the allotment saves us about £5,000 off our (Steve, Debbie, Tessa, Ollie, Jen, Jon and Robin) food bill each year and that saving easily covers all of the other food we buy and allows us to afford mostly organic.  We also gift another £5,000 to friends and family and that – if we were to sell it to them – would also cover our entire food bill with lots to spare.  So in value terms, but not monetary terms, we are financially self-sufficient in food.

The carbon footprint in the rest of our lives

Our current carbon footprint is already below the governments target for 2020, way below.  To improve things still further we buy renewable electricity and 10% renewable gas (the rest of the gas is offset).

We don’t fly, we turn the thermostat down, we line-dry our clothes, we use solar panels to fuel our dehydrator, fridges and freezer and we walk and cycle a lot.  However we still have a carbon footprint of about 6 tons.  The money we save on food from the allotment in a single week in spring means that we are in the fortunate position to be able to buy carbon offsets to cover this 6 tons and the carbon footprints of our children and their partners.

We understand that offsets are problematic, but most of that problem comes from people – for example – continuing to fly and using offsets, but not lifestsyle change, to make up for it.  In our case we have done everything that makes financial sense to reduce our carbon footprint.  Everything else requires new innovations or changes in government policy/regulations etc, we can’t directly affect these which leaves offsets as the only other option open to us, so we’ve taken it.

Summary

With a little effort (about 16 hours a week) and 250 sq metres of growing space, it’s possible to be self-sufficient in veg and seasonal fruit and to offset the total carbon footprint of all of the food we eat.  It’s also possible to save a lot of money, enough money in fact to buy all of our other food, if we decided to sell your surplus (not allowed as we have an council owned allotment) but also not desirable because it’s much better for us to gift it.

It’s also possible to save a huge amount of water.  Not all of that water saving will be in this country of course, but a lot of it will and it’s worth remembering that sustainability is a global problem and many of the counties where our food is grown have much less fresh water than we do, which makes this even more important.

As a spin off benefit while growing all this wonderful food: you can make top soil (a rapidly diminishing resource), improve the ecology of your environment, keep fit and have a lot of fun.

We try hard to grow the most food we can.  We take seriously how privilliged and lucky we are to have allotments and the positive impact we can have on global warming and sustanability in general as a result.  The more food we grow, the more water we save, the lower our carbon footprint, the less plastic used, the less food miles travelled, the healthier the community.  Of course the more food we grow, the more fun we have too, so it’s a win-win.

Fortunately we are not alone in this quest.  The town council and the allotment committee are equally committed to sustainability and our allotment site is full of passionate growers!

Finally bear in mind that this ‘analysis’ isn’t some government funded project undertaken by a team of economists and statasticians, published in a peer reviewed jounrnal.  It’s just a bit of fun, done one morning in a coffee shop, but I found it interesting nonetheless.