About Chemicals and their Alternatives
Eight mistakes about pesticides
Following a poll I made in gardeners/consumers in the frame of my study at the Open University (see my Environmental Study Curriculum), I stated that consumers are very aware of the harm that can result from pesticides, but some prejudices still persist...
Here are 8 frequent assumptions about pest control for which I could demonstrate the contrary.
“Pesticides in commerce have less damaging effects than the pesticides used in agriculture” / “The products sold in gardening shops are harmless”
The agents contained in gardening and agricultural pesticides are the same.
Moreover, the dosage recommended on the packaging of gardening pesticides can be up to 140 times (!) higher than the dosage recommended in agriculture.
“My individual use has limited effects”
The whole life cycle of a product have to be taken in account in order to estimate its impact: e.g. water bodies are heavily contaminated around the factories of industrial pesticides manufacturers. Also, pesticides persist a long time in the environment and combine with other agents and pollutants with unpredictable effects. Moreover, due to lack of information, gardeners often make an inadequate use of pesticides and underestimate their effects. For example, bee-keepers have stated important losses in their hives after weekends, during which gardeners assiduously attend their gardens. The mix of the different pesticides used by different gardener can moreover lead to synergistic effects, and therefore result in a toxicity greater than the sum of the effects of all individual pesticides.
“Pesticides on natural basis don’t have the damaging effects of chemical products”
'Botanic' pesticides like neem have a more restricted impact than chemicals but do affect non-target species. Especially insects at egg and larva stages are sensitive to them. You should use 'botanic' poisons only in acute situations.
“There are no or not many alternatives to pesticides”
Bio-gardening does offer many alternatives. Refer to the Pests List and the quoted references at the bottom of this page for more information.
“The commerce does not offer alternatives to pesticides”
Since bio-gardening offers methods rather than products than can be sold, do not count on shop sellers to advise alternatives that won't make the cash registers jingle. Nevertheless, a few brands like Neudorff do offer products based on alternative methods.
“The alternative methods are less efficient than chemicals”
Alternatives are as efficient as chemicals but will require some learning about the ecology of your garden and a good planning of your gardening activities.
“Some species can be eradicated without inconvenience”
The balance of ecosystems is very fragile. The breaking of one single link can have disastrous effects.
Each and every species have a role in nature, even if this is beyond our understanding. Do not destroy systematically non-breeding species in your garden: e.g., "weeds" can be an ally in your fight against pests, either as a repellent or as a habitat for pests predators. Refer also to "My Weeds" to discover surprising and useful information on 'weeds'.
“Pesticides are more practical to use”/“Pesticides offer a quicker solution for busy people like me”
If you really think this, you probably have not read the instructions of use correctly. These include the following instructions.
You should never allow skin contact with pesticides: If you manipulate powders or sticks, you should wear gloves. If you use sprays, you should cover all you body with impermeable clothes and wear eyes, nose and mouth protection. You should not allow anybody to stay in the vicinity of the plants being sprayed. If you do not follow those advices, you expose yourself and your relatives to acute poisoning.
Do not wash the clothes used for pesticide manipulation in the washing machine, do not empty pesticides remainings in the sink. All pesticides residues and everything that have been in contact with them (clothes, containers, packing, spraying bottles, etc.) have to be brought to a hazardous waste site. This is due to the fact that the elimination of pesticides from wastewater is a very costly procedure, while this procedure is not always applied by the local wastewater treatment company or the method used efficient enough. Dumping pesticides in wastewater raises thus social costs while still being a source of water pollution. The aquatic fauna is particularly sensitive to pesticides.
Do you still think that pesticides are convenient and allow you to save time?
What are the alternatives?
Refer the Pests List and the quoted references to know about alternatives to pesticides for your specific needs.
Biological control comprises:
- Mixed cultures: Some plants act as repellent on pests or have an antibacterial or antibiotic effect. Your can combine those plants with the plants you want to grow in order to protect them. Designing your garden in rows of plants that are susceptible to different pests will prevent an invasion of pest in extended parts of the garden. Moreover, rotating cultures from one year to the next one will diminish the chances of one pest to survive and persist for several years.
- Pest predators: Any organism is part of a food chain. Therefore, there will always be a predator to be found that will help you to control a pest invasion. Preferably, you should design your garden in order to offer a habitat to those animals: Refer to the The Insect-Friendly Garden and The Bird-Friendly Garden sections to find some hints on this topic. Otherwise, predator larvae can also be bought in specialised shops.
- Self-made recipes: There are many "granny's recipes" for self-made manures of broths in the case of an uncontrolled event. Preferably, you should also include growing the ingredients for those recipes in your garden, and, yes, that will require not destroying systematically any "weed" you see, since some of them, like Nettle (Urtica), will represent a precious ally in pest control. Refer also to the "My Weeds" section to discover surprising aspects of so-called "weeds".
- Crop rotation: Alternating each couple of years the cultivation of crops that are sensitive to different pests will prevent those pests from persisting year over year.
- Commercial products: You can find a number of ready-made products in gardening shops. Don't listen to sellers who assure that those products are inefficient and want to sell you a pesticide instead. My personal experience did not confirm this.
Literature about Pesticides and Biological Alternatives
In the English Language
Carson R., 1962: Silent spring, Mariner Book edition, Houghton Mifflin Company, Boston/New York, 2002. ISBN: 0 618 24906 0
In the German Language
Kreuter M.-L., 2001: Pflanzenschutz im Biogarten: Der Garten-Klassiker für die naturgemäße Abwehr von Krankheiten und Schädlingen. BLV Verlagsgesell-schaft, München. ISBN: 3 405 15980 6
Kreuter M.-L., 2004: Der Biogarten. BLV Verlagsgesellschaft, München. ISBN: 3 405 16674 8
Schlumberger A., 2004: 50 einfache Dinge, die Sie tun können, um die Welt zu retten und wie Sie dabei Geld Sparen, Westend Verlags, Frankfurt/Main. ISBN: 3 938060 01 8
Related Topics on this Website
Pests List: a list of pests that can appear in your garden or on your balcony with biological means to control them.