Organic gardening, is it viable?

Background . Key Points . Organic comparisons . No-Dig

There is a fierce debate about the viability of organic horticulture, with conventional growers claiming better and bigger crops, fewer diseases as well as  more efficient and cheap crops produced, whilst the Organic producers claim their plants are healthier, are grown with sustainability in mind (or as much as can be achieved in gardening) and preservation of natural resources and wildlife.

Background Organics

There is often an impression among customers that Organic = No Chemicals and therefore is Good however this almost incidental to the intent of organically grown produce.

True organic growing is based upon using natural and sustainable resources to achieve a useable crop whilst maintaining the environment and increasing wildlife diversity. This includes aspects such as the soil structure, beneficial insects and fungi, pollinators and ensuring the general health of the surrounding environs. It is this requirement that the local wildlife is unaffected. With commercially produced products, to be saleable as 'Organic' the crop must be certified by an agency (most often the soil association)

Organics dose not mean the garden must simply be left to nature and Instead many gardeners look to nature to understand how to improve their garden, such as mulching with manure rather than feeding with chemicals as the soil borne organisms such as worms are capable of using the manure to improve and feed the soil, this is possibly the most obvious and widely known difference between conventional and organic.


Important aspects of organic gardening

1. Protect the soil structure, a good soil means plants are better able to function, will develop better roots and be less prone to diseases, water logging and compaction.
  E.g. No-Dig system

2. No synthetic chemicals or non-sustainably gathered resources (with exceptions) (many synthetic chemicals require non-sustainable amounts of energy)
  E.g. Do not use Glyphosate (synthetic and wide spectrum) or Calcified Seaweed / Peat (non-sustainable)

3. Any organic chemicals (such as sulphur) should not be used if there is low risk / low damage or if they will negatively impact the wider environment (i.e. runoff)
  E.g. Pyrethrum near water

4. Nutrients should be added preferably via plant or possibly animal material rather than through chemical treatments (as this is how organisms are adapted to use it and as there are lower energy costs in use)

5. Pest and disease control should be handled via cultural and biological control rather than chemical
  E.g the use of Bacillus thrombosis ( an anti-insect bacterium) and pest predators or physically crushing pests.

6. Encourage biodiversity, A wide range of plants and insects will decrease the amount of disease and pest problems your garden suffers whilst providing natural predators with homes. Avoid using broad spectrum pesticides (or at least use them when there is little danger to other wildlife, spray before bees are active ext.)

7. Attempt to balance nutrients by crop rotation. This is general good practise and it helps reduce plant specific pathogen build up.
  E.g. Legumes --> Brassicas --> Root Veg (legumes provide nitrogen which brassicas use up and root vegetables little so the soil regenerates nitrogen)

8. Invest time, Whilst a No-Dig system will reduce weeds and increase soil structure it will take a lot of effort to initially achieve and removing weeds by hand properly is harder than spraying a chemical!

9. Even if you follow the organic garden guidelines to the letter this dose not make your garden organic, these rules are a voluntary code rather than a licenced definition used to produce organic products for sale.

10. Many products labled organic are not licenced organic, this can on certain products mean containing organic materials. E.g. Peat is an organic material but not licenced for organic in most uses.

This is a simplification of the guidelines for organic growing most useful for casual gardeners, The official guidelines are found Here (PDF), however they can often be overwhelming and their rigidity can be counter-productive if you do not have the time available to you. We would argue that some of the guidelines should be relaxed, for example the guidelines do not consider plastic protections to be organic whilst if you were to reuse plastic from other sources then it is comparatively sustainable.

The RHS provides its view Here on organic gardening Here and advocates a balanced perspective well worth reading.



The main issue seen with organic gardens is that they are less efficient and more expensive than traditional gardens. To an extent this is true, organics is a nishe and therefore there are less products and they tend to be more expensive, however organic gardens tend to have a higher organism count than conventional gardens do and they therefore have more natural predators. The greatest weakness of organic gardens would tend to be fungal infection as whilst some can be avoided, many problems simply are endured.


Comparisons of Organic vs Conventional garden chemicals

Garden Tool




Systemic Weed killer

Glyphosate (e.g. roundup)


With no systemic weedkiller certain weeds are harder to control with sprays and should be controlled by cultural means (e.g. Bindweed, dandelions)

Contact Weed killer

Diquat (Weedol 2)

Fatty Acids, Essential Oils,

These weedkillers generally destroy the waxy cuticle of leaves meaning they desiccate and that destroys the plants ability to grow and compete. Certain plants will require multiple treatments and it dose not affect roots that can act as a regeneration point for weeds. Best used on young weeds.

Lawn Weed killer

Hormone Based (Maxicrop, Vitax, Virdone)

Triclopyr based (SBK)


Lawn weedkillers use a synthetic hormone to cause every growth point on a plant, causing it to collapse and die. These hormones could theoretically be extracted from plants however the 'organicness' of these would be debatable.

Systemic Pesticide


None (sort of nematodes)

Theres are no organic systemic pesticides which can be problematic when dealing with insects such as scale or mealy aphid which are extremely resistant to contact pesticides. Nematodes can be used for certain pests however they can be killed by weather changes and are best used for greenhouses or sheltered gardens.

Contact Pesticide



Pyrethrum, found in Py is debatably organic, as it requires a great deal of energy to produce and whilst it is licenced for organic use (due to it being considered organic outside of the UK and its high effectiveness) it dose not fit in entirely with the organic ethos. (Pyrethroids have been used for centuries starting with native Americans using it to fish in the form of Derris root)

Fungicides Sulphur, Mycrobutinol, Copper Fish Oils Organic fungicides are greatly lacking when compared to their conventional counterparts, the most often used methods of control are to choose resistant plants and good garden practise such as removing dead or infected material.

Loose Fertiliser

Growmore, Vitax

Blood Fish and Bone

Whilst blood fish and bone has a reduced nutrient percentage (about  60-70%) compared to Growmore and is not as efficient as Vitax it is still a very viable fertiliser as it is provides organic matter to the soil in small amounts and it takes action over a longer period of time.

Bonemeal can also be used for autumn planting as a slow release fertiliser.

Liquid Fertiliser

Miracle Grow, Phostrogen

Organic Fertilisers

There are a number of organic liquid fertilisers on the market and the majority of them are not as efficient as the conventional comparisons, in particular tomato feeds which are high in potash. It would therefore be a good idea to apply slightly more regular doses.

Slug Killer


Iron Phosphate

Organic slug killers are a subject of hot debate amongst gardeners, They have the benefit that they are water resistant and the chemical doesn't leach. They are technically not organic with regards to produce for sale in the UK but they are considered better than the conventional alternative as they are less toxic to other animals and less likely to run into water.




Organic replacements are suitable for the majority of garden jobs however they tend to lack efficiency when compared to conventional tools and are often more costly. Herbicidal effects and fungicides are limited when compared to conventional methods.

Good gardening practise can make up for the loss in efficiency and keep organic gardens on par with conventional methods

It is perhaps wise to restate here that even if you use only organic products they can still be as dangerous to plants and animals as conventional products if misused, Spraying vinegar is often considered an organic method of controlling weeds but beware as it also acidifies the soil and is dangerous to certain beneficial organisms. These products are only considered sustainable if used sensibly.

Is Organic Better?

A lot of gardeners who garden organically claim their plants to be better, fruits to taste better and are more productive. Whilst this has never been proven for or against I personally belive the difference is largely down to the care shown to the garden, Organic gardeners are far more likely to notice problems on plants and prepare the soil properly because they often have a greater interest in it and need to treat it sooner in comparison to a chemical user who will spray and leave it alone.

If a plant is grown in well prepared soil that is looked after, cared for properly then there is really very little difference in the effectiveness of organic vs most conventional garden chemicals. A healthy plant will typically suffer less and recover more readily from diseases if it is affected at all. When a plant is not cared for fully however, then conventional garden chemicals are often quicker to act and more useful afterr a problem has appeared.


The No-Dig system

Traditionally gardens have been dug, providing a great number of benefits, this includes an increase in topsoil, the removal of perennial weeds and the breakdown of heavy clay structures. This is also an ideal opportunity to add fertiliser to the soil. There is however an organic technique increasingly popular called the No-Dig Method. It is ideal for gardeners who have a bad back (as many do) and whilst if you cannot produce much compost yourself, it can be expensive, on sandy or loamy soil it can be highly effective.

Ideally the soil should have an initial digging, this loosens up the soil and gives you the chance to remove any debris and perennial weeds. Ideally as this is the only chance you have to dig and prepare the soil, doing a double dig is ideal.

After this initial dig then the soil is covered by a mulch of 2" organic matter, either in the form of well rotted manure or compost. This is useful in two ways, firstly it smothers any annual weeds disturbed by the dig and brought to light, but it also provides organic matter to the soil which worms and other soil organisms will use to develop a deep topsoil.

This mulch is then repeated each year and over time the soil will improve and increase in depth. This has the advantage of greatly reduced weed germination as most annual seeds are activated with the appearance of light, meaning they are close to the surface and therefore they are stimulated to grow after digging.

This method works best on light or sandy soil with a good amount of worms, however the constant influx of organic matter will improve and benefit clay soils over time.


Traditional Digging vs Organic No-Dig
Traditional digging has the benefit of improving soil structure on heavy soils whilst removing perennial weeds. No Dig plots provide increased topsoil depth and loosened texture. Reduced annual weed germination
Traditional digging is free but requires hard work and is repeated year after year. No-Dig methods are costly if you cannot produce your own compost however they greatly reduce the physical work after a few years
Traditional digging allows you to remove debris and add fertiliser or lime throughout the soil. No-Dig encourages the local ecosystem and adds small amounts of nutrients to the soil. Provides a light structure to the ground.
Traditional digging works better than organic on a heavy or clay soil. No-Dig dose not damage the soil structure and works well on light sandy soils or open loams.
Is ideal for annual beds. Is ideal for vegetable plots.