A naturally occurring toxin produced by a fungus, commonly found on grains and seeds that have been exposed to moisture and high temperatures. It is particularly toxic to birds; any seeds or grains for bird feeding should be bought from a source that can guarantee their freshness and are free from aflatoxin. If in doubt, buy nuts and grains from a reputable source intended for human use, as these will have been routinely tested and certified to be aflatoxin-free.


The fourth commonest tree in Britain, the ash is a broad leaf deciduous tree, which has been used for its wood since Anglo-Saxon times. It is currently the dominant tree in our woodland.




Bacteria carry out a whole range of essential processes in the garden. Without bacteria, soil would not support life. Bacterial action at various temperature levels is one of the key mechanisms involved in composting

This is something that is capable of being broken down by micro-organisms, preferably in the presence of oxygen. In industry, there are global standards that specify by how much something must break down and the time is takes to do so before it can be classed as biodegradable.


Biodiversity is the term given to the variety of life on Earth. Reducing biodiversity can have a devastating effect on an ecosystem.

Boreal forests
These are the vast areas of forests in the northern hemisphere – just south of the Arctic Circle. Boreal forests travel through North America, Scandinavia, Russia and Canada, and consist of trees such as beech, larch, spruce and fir. In Canada, Boreal forest trees are used as a source of pulp for papermaking.



Clear cutting
The removal of all crops from a given area, usually destroying the area’s ecosystems and habitats – often never to recover.




When applied to plastics, the term ‘degradable’ means being broken down by chemical reactions rather than the activity of micro-organisms. Usually, they degrade without oxygen into water, CO2 and trace elements. The term degradable, like biodegradable, simply describes the potential of a product, but if it is disposed of incorrectly, any environmental benefits may be lost.

This is the re-use of resources to produce something of lesser complexity or value, while still saving energy and/or resources. This is normally a one-way process. An example is broken glass used as concrete filler. Once this has been done the glass will never be made into another bottle.




A level of organisation within the living world that includes both the total array of biological organisms present in a defined area and the chemical-physical factors that influence the plants and animals in it.



The term ‘forest’ has had several meanings in the past, but now refers to a predominately wooded area – although even now it can have several definitions. The term was introduced to England by the Normans, and originally referred to hunting land for the nobility.

These are very important decomposers in the compost heap and in the wider environment. They are one of the few organisms that can produce the enzyme that can digest wood.



Ground source heating
The heating at The Green House uses a ground source heat pump, where the ground is heated by solar energy, and this heat is used in the building. In warm weather, this can be reversed so that excess building heat can be pumped back into the ground.


Is a broad spectrum weed killer. If a weed killer absolutely has to be used (for Japanese knotweed for example), glyphosate is judged to be the least harmful as it poses little or no health risks to the user when used as directed, and it is deactivated by contact with soil.

Greenhouse gas

These are compounds, including carbon dioxide and methane, which are able to absorb and transmit infrared radiation and therefore have a critical part to lay in the regulation of our planets temperature. Without greenhouse gases, life would not exist on earth. It is also true that the increasing concentrations of these compounds are raising global temperatures. What isn’t yet agreed is what the effect will be of these increases.



The hawthorn is a broadleaf deciduous tree, also known as the May tree. The term ‘never cast a clout ‘til May is out’ refers to not removing your winter clothing until the May tree flowers – a sign of warmer weather. A clout is a 15th century term for shawl or cloth.

Human rights
The basic rights and freedoms to which all individuals are entitled.



In-vessel composter

These differ from a garden composter in that they use heat and/or agitation to accelerate the composting process. They can also raise the internal heat of the compost to ensure meat and fish waste can be composted safely by destroying harmful organisms like salmonella whilst allowing heat loving bacteria and fungi to thrive and break down the food waste.



Japanese knotweed

Is an extremely invasive plant, introduced into the UK in Victorian times as a decorative garden plant. Once established, it is very difficult to eradicate. As well as out competing native species, it can destroy property by growing through concrete, asphalt and even the foundations of buildings. Also known as ‘donkey rhubarb’ and ‘Japanese bamboo’, it is in the same family as dock, sorrel and bindweed.






A classic ‘rubbish dump’. It used to be thought that waste would rot away and eventually disappear when put in the land, but now we understand that rather than rotting away, waste ‘mummifies’ in a low oxygen environment. This means items like telephone directories and newspapers can still be readable after decades in the ground, and there have even been reports of fruit and hotdogs still being recognisable after thirty years in the ground.



This term encompasses all small insects and invertebrates that you may find in any habitat, including compost bins. Examples are millipedes which thrive on decaying organic matter, woodlice and earthworms.



Natural habitats
A habitat is a well-defined environment in which plants and animals live. Forest, wetlands, sand dunes and ponds are all examples of natural habitat.



Although there are over 600 species of oak, the species most common in the UK is Quercus robur – the English oak. English oaks are valuable habitats, providing home and food for more species of insects than almost any other tree in the UK. They also have symbiotic relationships with several fungi; truffles being a prime example.




Plantations are areas planted specifically to produce crops for commercial use. Forest plantations differ from natural forests in that the trees are normally grown in straight rows, and there is a limited range of tree grown – often a single species. It is an effective way of growing sustainable timber in that at least one tree is normally planted for each one cut down, but only if the land used for a plantation wasn’t previously of value ecologically.





These forests are defined by very high rainfall, with tropical rainforests (mostly around the equator) and temperate rainforests (more widespread). Rainforests have four distinct layers, each dependent on the others and each a habitat to thousands of unique plants and animals.

This is the re-use of resources to produce new items, saving energy and/or raw materials in the process. It’s sometimes repeatable – a good example is a glass bottle being remade into another bottle.




There are many different interpretations of ‘sustainability’. The most widely accepted definition comes from the 1987 Brundtland Commission: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Another key concept is the three pillars of sustainability: social, environmental and economic, and the understanding that for true sustainability all three need to be addressed equally.









Water footprint
A water footprint is the amount of fresh water used by a defined individual or organisation. Water footprints vary widely from country to country. For further information, visit www.waterfootprint.org.

Earthworms are critical to soil health, without them solid structure collapses and nutrient levels fall. They have a vital garden function of aeration and enrichment. Worms in your garden will turn over the top 15cm of topsoil every 20 years, performing a fundamental role in soil structure.