GREENER FINGERS - Sustainable Gardening

We all have a moral duty to behave in sustainable way across all aspects of our lives.

Growing our own food provides many opportunities in this respect. For example, our plots provide diverse habitats for wildlife (particularly insects) which can be further enhanced by restricting our use of chemical pesticides. By generating our own compost and using local sources of manure we can reduce our reliance on man-made fertilisers. These, and similar practices lead to healthier soils on allotment sites than those found on farmland with modern commercial agricultural processes;

The following sections describes ways in which you can grow crops without harming the environment and, in many instances, making a positive contribution to it.


Green manure

Organic gardening uses techniques which occur naturally – the word ’organic’ describes living organisms. 

Some people think that organically grown food tastes better but the proven benefits are safer growing (by using fewer potentially toxic pesticides and fertilisers) and protecting/encouraging wildlife. It can also reduce waste where compost is used by recycling kitchen and/or gardening waste. 

Organic gardening includes the following: 

  • Using natural mulches to restrict weed growth and retain soil moisture 
  • Using organic manures and peat-free compost 
  • Capturing and storing rainwater 
  • Cultivation processes with reduced or no digging 
  • Plant to encourage beneficial predators: birds, insects (ladybirds, wasps, lacewings…) and reptiles (frogs, toads and slow worms) 
  • Companion planting – plants which benefit each other (e.g. the onion family can be grown with carrots to deter carrot fly) 
  • Using green manure over winter to keep the soil warm and retain moisture 

It is not easy to be wholly organic but applying some of the principles will help to establish a natural balance on your plot. 

For more information see 

The 'No Dig' Method

Soil is a living mixture of diverse organisms and works better when it’s not disrupted. No-dig gardening can bring many benefits to your plot and is gentler on your back than traditional methods of growing vegetables. Nutrient rich materials – compost, manure, etc. – are applied at normal rates but only at the surface of the soil. Worms and other organisms do the work of bringing the nutrients into the ground.

The basic requirements are:

  • Avoid treading on areas where plants will be grown – this generally requires beds to be no wider than 1.2m (4’)
  • Regularly apply organic matter – well rotted horse manure, spent mushroom compost or maybe garden compost - over the ground surface to a depth of about three inches compost, manure and mulches
  • Apply nutrient rich fertilisers in the spring when plants are growing at their fastest and the weather is less likely to wash them away
  • Gently ruffle the surface when preparing seed beds
  • When beginning beds, apply opaque coverings (cardboard, carpets or sheeting) to kill of any weeds 
  • Beds that can be reached easily from both sides, avoiding the need to tread on growing areas
  • Regularly hoe out any weeds, and Hoe in – rather than dig over – any green manures

Earthworms, bacteria and fungi, all of which contribute to healthy soil, can be adversely affected by disturbance such as digging and by compacting soil. Most soil life is closest to the surface, and digging can bring poorer quality soil to the surface. Digging can also help seeds from weeds to find ideal conditions for growth.




Good compost is invaluable. 

Compost introduces nutrients to support plant growth. It lightens heavy soils, helps soils to retain moisture, and helps control plant diseases. 

Compost falls into two broad categories: garden compost and potting compost.

Garden Compost

Garden compost refers to the material that we can all produce when we gather kitchen and garden waste and leave it to decompose. Home-made compost ideally contains equal amounts of green materials (grass cuttings, fruit and vegetable peelings, young plants, animal manure, etc. which have a high nitrogen content) and brown materials (leaves, straw/hay, woody shoots, cardboard and paper). 

As the vegetable matter rots it generates heat. The heat accelerates the decomposition process resulting in rich, dark organic matter that can be dug into the soil or applied as a mulch. Adding materials such as nettles, comfrey and urine to compost can also help to accelerate the process. Oxygen is a key element in the decomposition process and garden compost should be periodically turned with a fork to introduce air.

Making compost helps the environment: reducing numbers of bonfires, cutting down on waste, and reducing demand for manufactured products. It can also provide a habitat for hedgehogs, beetles and slow-worms, many of which feed on slugs act as natural pest controllers, reducing the need for chemical pesticides.

Potting Compost

Potting compost is the bagged material that we get from garden centres (and The Shed!). Bagged compost is available in several forms to serve specific purpose – multi-purpose compost can be used at all stages in the growing cycle, seed compost is designed to assist germination, ericaceous compost is designed for plants which prefer acid soils, tomatoes and strawberries are planted directly in grow bags. Peat free compost is widely recognised as being more environmentally sustainable than those containing peat.


Plant Diversity



Growing many different types of plant close together creates several small natural ecosystems which, in turn, creates habitats for a wide range of creatures. This increases the chances of encouraging natural predators and helps to ensure that no single pest population is large enough to create problems.

Growing different plants together – companion planting – brings other benefits. For example, carrot flies are attracted by the smell of young carrot plants, but if strong-scented herbs or garlic/onions are growing amongst the carrots the carrot fly become confused.

A good approach is to plant some flowering plants between crops. Generally, these will attract hoverfly and ladybirds and occasionally bring further advantages – Cabbage White butterflies prefer to lay their eggs on Nasturtiums rather than cabbage plants, thus providing a natural decoy.

Other parts of the allotment can also support wildlife – log piles provide shelter predatory insects and compost heaps are ideal habitats for beetles and centipedes and provide a warm, safe haven for slow worms and hedgehogs.

Further information is available from the Br6thers web-site -

Local Manure


Manure is a great way of improving soil condition, available from the following local sources... 

  • Raybrook Riding, Bluebridge Road, Brookmans Park, AL9 7SX. Various ages of manure bagged for collection plus a “heap” which may be excavated. Parking for cars and trailers but please telephone before you arrive to check on availability. There is no charge, but donations to Horse Rescue are welcome. 

  • Welwyn Equestrian Centre, Arnolds Farm, Pottersheath Road, Welwyn, Herts, AL6 9SZ. They have two manure heaps which can be excavated for collection but you will need to supply your own bags and call the centre to notify them you are coming.

  • Riding for the Disabled, Rectory Road, Welwyn Garden City (opposite The Red Lion pub on the B197). Collect it yourself and you can make a donation to the charity on your visit.


Green Manures


Autumn is the time to plant green manures. These plants tend to grow quickly and either scavenge nutrients that otherwise might be washed out of the soil or take nitrogen from the atmosphere and transfer it to the soil through their root systems. The roots also improve the structure of the soil, and green manures also prevent weed growth by blocking out light to growing weedlings. 

The main types of green manures are listed below:

  • Clovers can help to fix nitrogen within the soil - should be planted between April and August.
  • Winter Tares (also known as vetches) is a good source of nitrogen and should be planted by September.
  • Phacelia (March - September) and Lupins (March - June) produce flowers which support bees and other insects as well as boosting the soil.
  • Italian or Hungarian ryes (August – October) are good to smother areas that have become overgrown with weeds and grows well through winter (but can provide shelter for slugs and snails).
  • Field beans can be planted as late as November and are good for heavy soils.
  • Mustard should be planted by the end of September and should be dug in after up to two month’s growth (or left as a mulch if the foliage is frost damaged).
  • Mexican marigolds (Tagetes Minuta) can be used as a green manure but its greatest benefit is that it suppresses bindweed and is best sown in spring.

Dig green manures into the soil in the spring while they are still soft and they add nutrients to the soil and enhance the activity of worms and other wildlife below the surface of the soil. Leave for at least two weeks before planting out crops.