Fermented tea is an effective and environment-friendly resource to fight most insects, pests and plant diseases.
It can be prepared from nettle, rhubarb, horsetail or comfrey. Here are the steps to prepare each and a summary of their specific advantages and characteristics.
Take note that generally, fermented tea is best used as a preventive treatment, and often cannot treat a disease once it has contaminated a plant.
These are the main fermented teas and decoctions for:
- Effectively fighting most garden and vegetable patch diseases.
- Supplementing essential nutrients that plants need to grow.
Fermented stinging nettle tea
This is one of the most common, since it serves to fight pests and can also be used to fertilize soil thanks to its high organic matter content.
- It enhances plant immune system response, which helps sprayed plants fight downy mildew, powdery mildew, or rust off. Note that fermented stinging nettle tea cannot cure these once the disease is there.
- Excellent aphid repellent.
Discover the technique on how to prepare fermented stinging nettle tea.
Fermented rhubarb tea
The advantage of this fermented tea is that it is ready to use within 24 hours.
- Fights against allium leaf-mining flies
- Excellent aphid repellent
Here is the technique to prepare fermented rhubarb tea.
This is an excellent way to fight the spread of most fungus, especially in the vegetable patch.
- It enhances plant immune system response, which helps sprayed plants fight downy mildew, European brown rot (rotting fruit), rust or peach leaf curl. Note that garlic decoctions cannot cure these once the disease is there.
- It is also effective against aphids, thrips and certain mites and ticks.
Here are the steps to prepare a garlic decoction.
Fermented comfrey tea
This is possibly the fermented tea that most organic farmers use. It contains very high levels of both potassium and nitrogen, which boosts plant growth for all plants in the vegetable patch.
- Use when watering all the plants in both garden and vegetable patch.
Here is the process to prepare fermented comfrey tea.
Fermented horsetail tea
This tea is a powerful defense against fungus-related diseases, especially on fruit trees.
- It enhances plant immune system response, which helps sprayed plants fight downy mildew, European brown rot (rotting fruit), rust or peach leaf curl. Note that fermented horsetail tea cannot cure these once the disease is there.
Here is the process to prepare fermented horsetail tea.
Additional ingredients and mixing weeds
Making fermented weed tea from different weeds
It’s perfectly possible to make batches of fermented weed tea by mixing material from different plants together. You’ll have the benefits of both.
Extreme fans of the process have a continually fermenting pot or barrel somewhere in their garden where they keep adding plant material as they weed the garden.
Crucial to the success of each fermented tea batch
Water – must be as close as possible to natural rainwater. Avoid tap water if possible. If you must use it, let it sit for at least an hour, at best a whole day, without a lid. Chemicals that keep it safe for drinking like chlorine will evaporate.
- Set up a rainwater collection system for your garden.
Trigger – usually enough micro-organisms are present on the leaves themselves to launch the fermentation. These are called epiphyte organisms, meaning they live on the plant without parasiting it.
- If ever it takes more than three or four days to start fermenting, you can add fermenting triggers to the mix.
- if you’re a fan of kombucha, you can add a slab of mother to the mix.
- keep some degraded plant material from your previous batch (whatever the weed), or start a new batch from the end of the previous one.
- a handful of ripe compost, vermicompost, or animal manure also does the trick.
- from the kitchen, you can add a live yoghurt or a spoonful of curdled milk.
Timing – you can harvest the weeds anytime, but fermentation starts fastest and nutrient conversion is highest when you follow these tips:
- set your weeds to ferment immediately after picking them. Don’t let them dry out.
- harvest your weeds early morning to collect the guttation fluid. Guttant is usually chock full of nutrients and trigger micro-organisms.
Other ingredients to make the fermented tea more potent
- Coffee grounds – It’s also possible to use some food specific scrappings from the house, such as coffee grounds. Simply add them to the recipe and the grounds will leach their nutrients into the fermented tea.
- Sugar – it may sound surprising, but sugar has been proven to help plants out. For example, birch trees recover from transplant shock much better with a mixture of sweetened water. Plain sugar will do, but you can also use molasses. Try to find non-treated materials (sugar cane molasses, etc) because additives like sulfur usually try to kill or control useful micro-organisms.
- Air bubble device – an old bubbler from an abandoned fish tank will create convection currents. The materials will mix out better and you won’t need to stir as often. It will prevent fermentation from turning into rot.
Last notes on fermented organic fertilizers & treatments
Put a cover on your fermenting weed tea to keep insects out. This will keep mosquitoes from multiplying and small animals from falling in.
Usually degraded plant materials are filtered out. This makes it easier for sprayers and watering cans. But you can keep them to trigger the next batch, enrich your compost or mulch needy trees with it!
Advantages of fermented tea over chemical products
The most important advantage is that this tea is “alive” as opposed to “sterile” products.
It creates and strengthens the ecosystem. Consider your plant as part of a community. Fermented teas try to build the community up and increase biodiversity. Chemicals are more single-minded about things.
|Insight||Chemical products||Fermented tea|
|Mode of action||Harms the pests||Empowers the plant|
|Effect on plant||Weakens the plant||Strengthens immunity|
|Effect on beneficial animals||Eliminates them, too||Usually not impacted|
|Effect on soil||Slowly sterilizes it||Makes it richer|
|Effect on water||Leaches to the watertable||None|
|Effect on humans||Toxic warnings
|Depends on weed used,
some can even be drunk
|Repeatability||Repeat application at
each new infection.
need to repeat decreases
|Long-term effect||Pest develops resistance
|Plant develops resistance
|Battlecry||Kill them all!||Crowd them out!|
There are a few disadvantages, which are mostly related to how we organize our work. Indeed, chemical products are just a click away online, or a short drive to the garden center. They’re usually immediately effective and make for faster treatment.
Why does fermented tea work?
Plants never exist “alone” in their environment. They are surrounded by living creatures. We’re familiar with most insects and caterpillars, but there are also microscopic members in this community.
Plants are part of a living ecosystem
Epiphyte micro-organisms are those tiny germs, fungus, yeasts, molds and mites that live on the surface of plants. They cover leaves, stems and trunks.
Mychorrhizae are underground fungi that work with plants together to extract nutrients from decaying material and available minerals.
Fermented teas develop lots of yeasts and beneficial germs. Spraying on both leaves and soil helps. They make the plant’s work easier by:
- providing nutrients,
- strengthening the number and diversity of micro-organisms
- crowding out harmful germs.
The technical term for this is “infection antagonists”, meaning they fight infection together with the plant.
In a way, one can say “it brings out the best in all of us”, since even us humans are made more aware of the intricate beauty of nature!
Science proves effectiveness of beneficial yeasts and bacteria
In an experiment involving beneficial yeast and bacteria on tomato plants, a significant reduction in infection was noted. This was conducted with the Septoria fungus, a common cause of leaf spot.
Infections were reduced by 20 to 80 % compared to untreated specimens. Results varied depending on the yeast and bacteria used, but every case showed an improvement against the control sample.
Working these natural solutions into your usual gardening routine will work wonders for the garden, your wallet, and everybody’s health, including the planet’s!