Martin in a keen gardener; he is passionate about growing his own fruit and vegetables for himself and his family.
Growing fruit and vegetables organically is a priority so when it comes to crop rotation and planting new seedlings Martin has a major concern.
“How can I get rid of bacteria in my soil without using chemicals?”
The soil in his garden and greenhouse that was used for growing the previous season’s crops needs to be sterilised to ensure there are no remaining bacteria or pathogens, making it ready for the next crop.
Previously, Martin has treated his soil with Jeyes Fluid, as have countless other gardeners. He is growing increasingly concerned about the impact these chemicals are having on his crops, his environment and his family.
In years gone by, Jeyes fluid has been effective at killing a whole host of bacteria and fungi in a large number of outdoor jobs, such as:
- Deodorise drains
- Clean water butts
- Disinfect patios
- Clean wheelie bins
- Clean greenhouses
- Clear paths
- Disinfect animal housing
- Disinfect stables
- Farm cleaning
- Killing avian flu
Jeyes Fluid still, to this day is used for these (and other) outdoor disinfection jobs but at what cost?
There are 5 important reasons why Jeyes Fluid should be avoided:
- Contains harmful ingredients
- Dangerous around animals
- Ill effects on people
- Adverse effect in the garden
- Bad for the planet
The popularity of Jeyes Fluid is not through choice it had been bred from tradition and a lack of eco-friendly options on the market.
You can read more about the harmful ingredients and ill effect of Jeyes Fluid here
How can I sterilise my garden soil WITHOUT chemicals?
When you look online you will find a few suggestions as to how to rid soil of pathogens without chemicals, a popular method used is baking the soil in an oven. This is not always going to be a practical solution given the size of some gardens and plots. Thing is we CAN bake soil, and lots of it, using the sun.
What is soil solarisation?
Soil solarisation is based on the principles of oven baking soil, to increase the temperature to a high enough level to kill bacteria, but on a much larger scale.
Heat (when at a high enough temperature) kills bacteria by breaking down the enzymes and effectively rendering them harmless.
How do I sterilise soil using solarisation?
10 steps for effective soil solarisation:
- Clear the area you want to sanitise by removing any plants or crops (biomass)
- Make sure all roots are removed from the ground
- Rake the area and remove any remaining seeds or broken roots
- When raking, try and create a small hump to allow for water run-off
- If the soil is very dry, dampen by hosing - do not soak
- Lay clear UV resistant plastic over the area
- If the plastic is thin, double it up
- There needs to be good contact with the soil so weigh down the edges of the sheeting with batons, rocks or other soil.
- Be careful to not rip or pierce the plastic
- Leave for 6-8 weeks
How long does it take for soil solarisation to work?
The length of time it takes for soil solarisation to be effective is dependent on the climate. If you live in a typically warm country, 4-6 weeks should be sufficient time for the process to eradicate harmful pathogens. However, if your climate is cooler the process will take up to 8 weeks.
What are the advantages of soil solarisation?
Soil solarisation uses the planets natural resources (the sun) to rid the patch of earth of bacteria and disease. There is no need to use harmful chemicals or pesticides which, in turn, reduces your impact on the environments, humans and animals.
What temperatures have to be reached for soil solarisation to effective?
The temperatures needed to be effective are relatively lower that you would expect. This chart shows the temperatures achieved with and without polythene covering (mulch):
As long as your soil is damp before you cover it with polythene, it is at its optimum condition to allow the heat to build.
In a scientific paper produced by Charles N. Merfield it details “Adequate soil moisture during solarisation is crucial to increase the thermal sensitivity of the target organisms, improve heat conduction in the soil, and enable biological activity during solarisation”
You can download the scientific paper on soil solarisation here
Are there any drawbacks with soil solarisation?
There are advantages to soil solarisation that definitely outweigh and disadvantages or attributed limitations:
Advantages of soil solarisation:
- No adverse effect on the environment, humans or animals
- Low cost - the plastic sheeting can be used time and time again
- Straight forward process
- No negative chemical effects on the soil
Disadvantages of soil solarisation:
- The method is dependent on climate so may be limited at certain times of the year
- Crops cannot be planted in the soil during solarisation
Can polythene sheeting be recycled?
When buying the plastic sheeting for your project, be midful of the type of plastic the sheeting is made from. You will want to be able to recycle it at the point it becomes ripped or has holes in it. We wrote an article on recycling plastics that you may find handy:
This method of ridding your garden soil of bacteria is relatively cheap (cheaper than chemicals), it is simple to carry out and very effective so what would stop you trying it?
It takes a little bit more effort to treat a garden using this method as opposed to spraying chemicals or pesticides. But the benefits of using soil solarisation are worth that little bit effort.
We know that it is extremely important for growers to move towards using products that are as environmentally friendly as possible, and we also know that it doesn’t stop at the growing stage; Eco-friendly garden cleaners are needed to stop the spread of disease before the plants have even been potted.
We wrote this article on the eco-friendly garden cleaner options available online
We also looked into butts, water butts and the sustainable options available for cleaning them, you can read that here
Making that little bit more of an effort can be applied to numerous situations;
Recycling – it takes a little bit more thought and consideration to recycle rubbish rather than throw everything in landfill.
Food – In order to eat healthy nutritious food it takes a modicum of effort and forethought
Exercise – A strong mind, determination and effort is needed to be active and more importantly be consistent
Relationships, work, kids, reading, writing; this list goes on …
Lack of effort and increased 'convenience' for consumers is a contributing factor to why the planet is in the state it is today. If each and every one of us took stock of our actions, slowed down and made a concerted effort to improve, can you imagine the positive effect it could have on the world around us?
Making changes in the products we use, the food we eat and how we stay healthy and active can seem like a daunting task.
Where do you start?
Where do you find the time?
Maybe you have you made some changes but don't know what else you can do?
Our ‘Detoxify your life’ project could help you along the way; one email each month with helpful suggestions to detoxify your life one step at a time – interested?
All the links in this article can be found here: Free Downloads: Science Direct Scientific Paper 10 Steps to soil solarisation (poster) For reading: Eco-friendly garden cleaners available online