In these times of global uncertainty and transition, where the globalised food system has become halted or reduced1, there is a wonderful opportunity to begin practicing food sovereignty on a personal basis2. This seems to be being put into practice in many places as growing one’s own food becomes more popular around the world3.
Being able to harvest and consume something which you have cultivated in the soil can be a very satisfying experience, from a practical point of view, as well as looking at it from the perspective of spiritual and mental well-being4. We can be seen as directly participating in the cycles of nature when we care for plants, especially if we choose to do so without the use of chemicals. Yet what if the beautiful vegetables we have so lovingly brought up are threatened by other creatures who also find them delicious to eat?
Permaculture practitioners have an answer to this: to intentionally include elements (whether plants or animals) in your garden which provides predators for those animals who would otherwise make your crop their prey. This technique, known as Integrated Pest Management (IPM)6, can be exercised in a number of ways, and there appear to be some important factors to remember when applying it with your crops, in order for it to be successful. This article will explore how IPM works, and how we can use it as part of a holistic design, while part 2 will give some practical examples to help with your own pest management on any scale; whether you are planting a few herbs on your balcony or have a large piece of land.
What is IPM?
As Bill Mollison is often quoted as saying, “you don’t have a snail problem, you have a duck deficiency” 7 – a quote which in many ways sums up how IPM works. The key is to look at the animals or plants which are already present or likely to become present in your system, and if some of them are unwanted, to introduce garden design or other measures which may repel them, or other animals or plants who are their natural predators.
As a technique with this name, IPM was first developed in the USA in the 1950s and 1960s in response to criticism of “organochloride” pesticides such as DDT8. One of the most well-known and perhaps poignant of these criticisms is Rachel Carson’s Silent Spring, from which we can read:
“The question is whether any civilisation can wage relentless war on life without destroying itself, and without losing the right to be called civilised.”9
Ten years later the US government banned the use of DDT in farming10.
Balancing Natural Cycles
Though the specific technique of IPM was developed in the past half-century or so, it is quite likely that humans have been incorporating some similar techniques into the way we grow things for many millennia. For example, in parts of the Amazon rainforest, where it is thought that humans have been cultivating crops not by destroying the forest but by mimicking the natural ecosystem for over 10,000 years11&12. Part of this cultivation (which we may now call food forest gardening) may well have involved some form of integrated pest management.
It seems important to remember when putting IPM into practice that in order for it to be effective we need to embed it in ecological thinking; that is, consideration of the ecology, or web, of the whole system.
The Spectrum of IPM
To me, it seems that IPM can be broadly divided into a number of distinct forms which could be more or less summed up as follows:
- Implementation of non-alive specific design elements which repel the ‘pests’, e.g. blocking a hole in the wall so that it is less easy for cockroaches to enter your kitchen.13
- Implementation of non-alive specific design elements which will attract predators of ‘pests’ e.g. installing bat boxes to attract these predators of mosquitoes.14
- Cultivation of specific plants as “companion plants” which have repellent properties, e.g. planting marigolds next to potatoes so that the potatoes can benefit from the allelopathic, nematode-reducing properties of the marigolds.15
- Cultivation of specific plants which attract so-called “beneficial insects”, or predators of the ‘pests’ e.g. planting caraway or coriander to attract lacewings, whose larvae eat aphids.16
- Introduction of animals whose diet includes the ‘pests’ e.g. introducing ducks into your system so that they will eat snails.7
I would say that these forms of IPM are part of a spectrum, with 1 being the least obtrusive to the overall balance of the ecosystem, and 5 being the most. Because of this, I would suggest trying those outlined in 1 – 4 first before considering the addition of any creatures into your ecosystem, simply because it would mean a lot more management and design on your part.
To take Mollison’s example, it is probably not enough to simply recognise that snails are unwanted and ducks are predators of snails, if you do not consider how the ducks will fit in with the other elements of the system. Ducks also eat plants; how would you stop them eating your vegetables? These and other factors would need to be considered (ideally by performing an input-output analysis) 17 & 18 before the addition of any predatory animal.
To Kill or Not to Kill?
Many practitioners of IPM would also add a sixth form, which would be the introduction of insecticides or other hazardous chemicals13. Whether you decide to incorporate chemicals into your own personal IPM is entirely up to you and everything needs to be looked at on a case-by-case basis. Even Carson did not suggest stopping the use of chemicals entirely;
“It is not my contention that chemical insecticides must never be used. I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm.” (9)
So if you have considered the potential for harm and the rest of the spectrum of IPM and do not have another way to repel a particular pest, then the use of chemicals may well be right for you in some cases. As Anne- Marie Poirrier says,
“Chemical treatment, no matter how low the hazard, should only be resorted to after all physical and cultural options are exhausted. We should learn to live with, and appreciate, the smaller inhabitants of the region, rather than poison ourselves and environment in the vain attempt to ‘eradicate’ pests.” 13
Putting the Spectrum into Practice
Now we have explored what IPM is and its implementation as part of a balanced system, we are ready to begin putting it into practice. This article has given a few examples of IPM as part of a garden; in the next part we will look in more detail at practical ways you can incorporate IPM into your own systems.
- Gunia, A, 2020. ‘How Coronavirus Is Exposing the World’s Fragile Food Supply Chain – and Could Leave Millions Hungry’. Time, 8/5/20. https://time.com/5820381/coronavirus-food-shortages-hunger/ – retrieved 16/6/20
- Ashwanden, C, 2020. ‘Planting Seeds in Crisis’. Permaculture News, 8/4/20. https://www.permaculturenews.org/2020/04/08/planting-seeds-in-crisis/ – retrieved 16/6/20
- Chandran, R, 2020. ‘Grow Your Own: Urban farming is flourishing during the coronavirus lockdowns’. World Economic Forum, 9/4/20. https://www.weforum.org/agenda/2020/04/grow-your-own-urban-farming-flourishes-in-coronavirus-lockdowns – retrieved 16/6/20
- Yu, A, 2020. ‘Fearing Shortages, People Are Planting More Vegetable Gardens’. NPR.org, 27/3/20. https://www.npr.org/sections/coronavirus-live-updates/2020/03/27/822514756/fearing-shortages-people-are-planting-more-vegetable-gardens – retrieved 16/6/20
- Kumar, S, 2013.Soil Soul Society: A New Trinity for Our Time. Leaping Hare Press: Brighton, UK.
- Deep Green Permaculture, 19/11/19. ‘What is IPM?’ https://deepgreenpermaculture.com/2019/11/19/what-is-integrated-pest-management-ipm/ – retrieved 16/6/20
- Mollison, B; Slay, RM, 1991 (2000). Introduction to Permaculture. Tagari Press: Tasmania, Australia.
- Biocontrol Reference Center, 2020. ‘The History of Integrated Pest Management (IPM). http://www.biconet.com/reference/IPMhistory.html – retrieved 16/6/20
- Carson, R, 1962 (2002). Silent Spring. Houghton Mifflin Company: Boston, USA.
- National Biomonitoring Program, 1972. ‘Dichlorodiphenyltrichloroethane (DDT) Factsheet’. https://www.cdc.gov/biomonitoring/DDT_FactSheet.html – retrieved 16/6/20
- Davis, N, 2020. ‘Humans living in Amazon 10,000 years ago cultivated plants, study finds’. Guardian, 8/4/20. https://www.theguardian.com/world/2020/apr/08/humans-living-in-amazon-10000-years-ago-cultivated-plants-study-finds – retrieved 16/6/20
- Meyer, R, 2017. ‘The Amazon Rainforest Was Profoundly Changed by Ancient Humans’. The Atlantic, 2/3/17. https://www.theatlantic.com/science/archive/2017/03/its-now-clear-that-ancient-humans-helped-enrich-the-amazon/518439/ – retrieved 16/6/20
- Birkeland, J (ed), 2002. Design for Sustainability: A Sourcebook of Integrated Eco-Logical Solutions. Earthscan Publications: London, UK.
- Ober, H, 2013. ‘Bats: An Excellent Addition to Your IPM Strategy’. University of Florida IFAS, 25/10/13. https://nwdistrict.ifas.ufl.edu/phag/2013/10/25/bats-an-excellent-addition-to-your-ipm-strategy/ – retrieved 16/6/20
- Wang, K-H, 2010. ‘Using marigold ( Tagetes spp.) as a cover crop to protect crops from plant-parasitic nematodes’. Applied Soil Ecology, 46(3):307-320, November 2010. Summary available here: https://www.researchgate.net/publication/251619817_Using_marigold_Tagetes_spp_as_a_cover_crop_to_protect_crops_from_plant-parasitic_nematodes – retrieved 16/6/20
- Hoffman, F, 2014. ‘Plants That Attract Beneficial Insects’. Permaculture News, 4/10/14. https://www.permaculturenews.org/2014/10/04/plants-attract-beneficial-insects/ – retrieved 16/6/20
- Permaculture Association UK, 2020. ‘Input-Output Analysis’. https://www.permaculture.org.uk/design-methods/input-output-analysis – retrieved 16/6/20
- Hablutzel, O, 2010. ‘A Report on ZERI Training Course (Zero Emissions Training Initiative). Permaculture News, 18/1/10. https://www.permaculturenews.org/2010/01/18/a-report-on-zeri-training-course-zero-emissions-research-initiative/ – retrieved 16/6/20