How to Create Closed-Loop Garden Systems

Closed-loop garden systems should lie at the centre of every sustainable garden. Creating them can sometimes be challenging. But aiming for entirely closed-loop garden systems should lie at the centre of all modern gardening endeavours.

While we may not be entirely successful all at once, making this a goal of our gardening can help us to make sure that we are moving in the right direction.

What is a Closed-Loop Garden System?

Closed-loop garden systems are systems that require no external inputs, and which produce no waste over time.

Instead of producing waste, the systems funnel byproducts and excess back into the system, creating circular systems that really can stand the test of time.

Closed-loop gardens do not need compost or other enrichment materials to be purchased from a garden centre or another shop. They do not need water other than that which rises naturally below the soil on the land, flows through it, and falls from the skies.

They themselves create the materials needed to maintain healthy soil and good fertility and healthy plants. And the plants can even be propagated by the gardener to avoid the need to buy in new plants and seeds.

Why is it Important to Aim for a Closed-Loop System in a Garden?

When we think about creating a closed-loop system in a garden, we have to take a close look at what we put in, the interactions between different elements and systems in a garden, and what we take out. This helps us to see things more clearly, and become better and more sustainable gardeners over time.

First of all, by creating closed-loop systems in a garden, we can reduce the amount that we need to purchase or bring in to achieve our other garden goals, to create a beautiful environment and to produce a yield.

Reducing consumption is of course often a key goal in sustainability. It not only saves us money. It also reduces our carbon footprints as individuals and households, and allows us to withdraw our support from finite, damaging and fragile systems elsewhere.

A closed-loop, circular garden system is a stable one – one with great diversity, with multiple elements to fulfil every function and multiple functions fulfilled by each element. It can be a resilient system, far more likely to endure over a longer period of time, regardless of external factors.

Important Considerations in a Closed-Loop System

When we are aiming to create closed-loop systems in a garden, there are a number of key areas on which we should focus:

• Water
• Soil
• Fertility
• Waste Management & Reuse
• Making the Most of Time and Space

When you are aiming for a closed-loop garden system, you need to give some careful consideration to each of the above. So let’s take a closer look at each of these categories to help you understand exactly how you can move closer to your end goal in each of these key areas:

Water

In a closed-loop garden, we need to be very aware of where the water we use will come from and how much of it we use.

In order to make our efforts sustainable we need to be using natural rainfall in order to irrigate/ water our plants, and perhaps also considering grey-water systems. And we need to be thinking very carefully about how we catch and store water on our properties, and how we might direct that water to meet our needs in the garden.

Freshwater use of course is something that drags us out of the immediate loop of the garden systems. But when we operate sustainably, we should be allowing for the perpetuation of broader natural cycles.

As we catch and store water on our properties, we can harness it while still allowing natural cycles to continue – sometimes even shortcutting those cycles as we use water wisely within our space.

In certain gardens, especially where natural rainfall may sometimes be in short supply, it can be a good idea to take things a step further still, and make sure that water can recirculate quickly within a particular type of closed-loop garden system.

By creating a hydroponic, or better yet an aquaponic system, we can use far less fresh water, and allow a shorter water-related loop. Water circulating in a sustainable aquaponics system can go through that system, with nutrients added by fish and micro-organisms, and then used by plants, again and again.

Soil

Where we are not exclusively growing plants in water-based growing systems, soil is of course another essential element to think about when trying to create closed-loop garden systems.

The plants in most gardens will of course obtain much of what they need (aside from sunshine and carbon dioxide) from the soil in which they grow. And so we neglect the soil below our feet at our peril.

The soil is essential. It really cannot be overlooked if you really want to create self-perpetuating, healthy systems in your garden.

If we are not careful about how we manage our gardens, soil becomes a finite resource that we are damaging and potentially depleting over time. But in sustainable gardens, we can care for and build the soil upon which we depend as the years go by.

Taking care of the soil means taking steps to keep living roots in the soil over as much of the year as possible. It means avoiding leaving large areas of bare soil, and reducing compaction issues by avoiding stepping on or compressing the soil in our growing areas.

It also means, of course, using resources from the garden itself in order to maintain a good diversity of soil life, and a soil that is rich in organic matter.

Fertility

Creating closed-loop soil systems also means taking steps to replenish the nutrients that plants take from the soil in growing areas over time. And thinking about where we will obtain the ingredients to do so.

In a well designed garden, we should think about planting not only to produce food and other resources for household use, but also to produce yields that can be channelled back into the garden to maintain its health and fertility over time.

We do this through measures such as planting nitrogen fixers and other dynamic accumulator plants to chop and drop, through the use of other organic mulches, and through the use of deciduous trees and other plants that will add organic matter naturally to the soil each year.

We can also perpetuate our growing systems more effectively by making use of natural fertilizer materials – not only for mulches but also to make liquid plant feeds.

We may have specifically planted certain plants (like comfrey, for example) to make these feeds. But we can also make use of naturally-occurring wild plants that pop up in our gardens as ‘weeds’ (like nettles for example) as well as those that we have chosen to cultivate ourselves.

Waste Management & Reuse

In a closed-loop garden, nothing should be wasted and nothing should be thrown away. Of course, any sustainable garden will have some composting system in place – likely more than one composting system will be used to manage organic material within a garden.

There should be zero food waste when we are aiming for truly sustainable, closed-loop systems in a garden.

We should make full use of each of the crops we grow – their primary and secondary yields – in our kitchens and around our homes. What we cannot make use of, we should be sure to turn into compost to return nutrients to the soil, no matter what different composting systems we decide to use.

Of course, reducing waste is not just about food scraps, other organic matter, or any compostable waste. It also means using water more wisely to prevent its waste, and thinking about other forms of waste that might come from not making the most of the natural resources or gifts of nature around us.

From weeds, to grass clippings to hedge prunings, to dead wood – no natural materials should leave your garden, and each can be used around the space to reduce consumption and close the loop on garden systems.

Making the Most of Time and Space

When we are aiming to create closed-loop garden systems, we need to make the most of all that our gardens can provide, however large of small they may be. That means making the most of the time and space available.

When you really think carefully about what can be achieved in any garden, you will be amazed by just how productive spaces can be and just how much can be achieved.

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