Soil is the foundation of a thriving vegetable garden. It is not merely an inert growing medium, but a living, breathing thing that we can nurture if we pay attention to its needs. In turn a healthy soil will reward us with robust plant growth that is more disease-resistant, as well as improving local biodiversity.
Sustainable soil improvement focuses on building a fertile, nutrient-rich soil rather than having to reach for synthetic plant feeds or soil amendments. Short term soil amendment measures are often a temporary fix that can deplete long-term soil health over time - in much the same way as a morning coffee isn’t the ideal solution for long-term sleep deprivation.
A healthy, well-structured soil makes it easier for plant roots to absorb essential nutrients, moisture and oxygen.
A healthy garden soil should be teeming with life: earthworms, soil microbes, nematodes, fungi and insects, all playing an interconnected role in the soil ecosystem. These tiny organisms help break down organic matter into nutrients that plants can readily absorb.
When soil life thrives, plants are more resistant in the long term to pests, diseases, and environmental stress.
Living inhabitants such as earthworms also improve the structure of your garden soil, opening up air pockets and burrowing tunnels. This leads to better aeration (essentially the opposite of compacted soil) and drainage (which prevents damp, waterlogged soil).
Nurturing soil health is the key to all that follows in the vegetable garden. Adding plenty of organic matter - in the form of compost, broken-down manure, leaf mould or living mulch materials - will ensure that your garden soil is rich, well-structured and abundant in beneficial organisms.
Making your own compost is a great way of having a consistent supply of broken down organic matter, created using household and garden waste. With insulated, rapid composting units you can produce compost all year round.
You can also buy in compost, which is particularly recommended if you are looking to add compost with a higher nutrient content, a more consistent or finer texture or a more complete range of nutrients and trace elements.
Envirogrind compost, for example, contains a high percentage of composted fish waste as well as other food waste from the facility in Killybegs where it is produced. It’s intended as a soil improver and can be added as a springtime mulch or top dressing, or mixed with other composts to boost nutrient content.
For the sake of sustainability and eco-friendliness, we should seek to use peat-free or peat-reduced composts. Peatlands or peat bogs are vital mini-ecosystems that absorb and store carbon dioxide, as well as providing habitat for various threatened wildlife species.
Digging or cultivating your garden soil can disrupt fungal networks and damage the soil structure. Many gardeners - including influential figures like Charles Dowding - have adopted a ‘no dig’ approach to soil improvement, where organic matter or living mulches are added to the soil surface and left to break down or be transported below the soil surface by worms etc.
No dig gardening mimics the natural process that takes place in woodland environments (for example). Nutrients are released slowly as the organic matter breaks down over time. ‘No dig’ minimises soil disturbance, while also reducing the amount of back-straining work you need to do in the garden.
Cover crops offer us a natural method of protecting bare soil when the vegetable garden is dormant. Also known as green manures, examples include Vetch, Clover, Buckwheat or Field Beans.
One of the main benefits of sowing these cover crops is as a form of natural, organic weed control at a time when soil would otherwise be more vulnerable to weed growth. However they also have added benefits such as nitrogen fixing (in some cases), promoting good soil structure (via their roots) and preventing soil erosion.
If these crops are left to complete their life cycle and break down naturally, they will add more beneficial organic matter to the soil.
Other methods of weed prevention - without the use of synthetic weedkillers - include placing cardboard mulches or weed fabric over the soil.