discover the potential of plant-based brews as effective natural fertilizers, insecticides, and repellents and learn how to harness their power.

Harnessing the Power of Plant-based Brews: Effective Natural Fertilizers, Insecticides, and Repellents

GardenBy Jun 18, 2024

The Power of Plant-based Brews: Effective Natural Fertilizers, Insecticides, and Repellents

Gardening enthusiasts and home caretakers are increasingly realizing the potential of plant-based brews as effective natural fertilizers, insecticides, and repellents. These concoctions, known as plant extracts or fermented preparations, have been used for centuries to strengthen plants, enhance their resistance to climate changes, and deter or eliminate harmful insects.

It is important to note that plant-based brews are highly concentrated and should never be used directly on plants. Even though they are natural, excess use can be detrimental. Let’s delve deeper into these fermented plant extracts and understand how to harness their power for sustainable gardening practices.

Plant-based Brews: What are they?

Throughout history, humans have relied on natural preparations, often derived from plants, to care for their cultivated plants. However, the advent of mechanized and industrialized agriculture led to the widespread use of chemical products that posed significant dangers to the environment and human health.

In recent years, there has been a growing awareness of the harmful effects of agrochemicals on the environment and human well-being. As a result, many farmers have transitioned to organic farming practices that emphasize sustainable, natural approaches. This shift has also brought plant-based brews into the spotlight.

The Battle for Recognition: A Brief History

The governments, likely under pressure from agro-industrial lobbies, have resisted the official recognition and market availability of these natural preparations. Despite the 2008 “Grenelle de l’Environnement” which aimed to reduce pesticide use by half within ten years, pesticide sales continued to rise. However, gardeners have still enjoyed a tolerance for using plant-based brews.

  • January 6, 2006: The French agricultural orientation law prohibits the sale of non-approved phytopharmaceutical products, including plant-based brews that fail to meet the same standards as chemical products. However, gardeners are allowed to use them.
  • May 5, 2011: An official decree authorizes the commercialization of nettle-based brews but fails to mention other plants that can be used as brews. This decision is met with opposition from the Association for the Promotion of Low-Risk Natural Products (Aspro-PNPP).
  • April 27, 2016: A decree establishes a simplified authorization procedure for natural substances used as biostimulants or “preparations peu préoccupantes” (PNPP). It lists 148 substances such as nettle, garlic, and ivy but excludes plants like fern or comfrey.
  • June 14, 2021: An official decree grants authorization for natural substances used as biostimulants, including edible plant parts used in natural preparations that meet specific criteria. However, there is still no specific regulation for non-edible plants like rhubarb or fern.

As a gardener, you are free to use these low-risk natural preparations or plant-based brews without any cost. Homemade brews can offer a sustainable and affordable alternative to commercial products.

Preparing Plant-based Brews

Plant-based brews are rich in nutrients, fungicides, repellents, insecticides, or insect repellents, depending on the plants used. They serve as a clean substitute for chemical pesticides and herbicides.

To prepare a fermented extract or brew, you only need a few basic supplies: a container, water, and plants. Choose a container made of glass, ceramic, or plastic (avoid containers that previously held agrochemicals). Preferably, use rainwater, which has been filtered to remove debris and impurities. Select plants that have not been exposed to chemical treatments and cut them finely.

There are a few essential guidelines to follow when preparing plant-based brews. Firstly, ensure the ambient temperature is not too cold, as microorganisms essential for fermentation may struggle below 15°C (59°F). Ideally, maintain a temperature between 20°C (68°F) and 25°C (77°F).

Regular monitoring and daily stirring are necessary to track the fermentation process. Each brew must be prepared separately. Avoid mixing different plants, as it may have adverse effects. Some advise adding lavender, sage, thyme, or hyssop to repel pests such as ants, slugs, or aphids. However, it is not recommended as the essential oils in these herbs may hinder fermentation.

Additionally, it is best not to add garlic, shallots, or onion waste preventively against fungal diseases. To ensure successful fermentation, it is advisable to prepare sufficient quantities. After filtration, plant-based brews can be stored in sealed plastic containers, labeled correctly, and kept in a cool place.

The Properties of Each Plant-based Brew

Plant-based brews can be used for watering or spraying, following the recommended dilutions for each recipe. It is advisable to avoid application during hot periods when the properties of the fermented extracts may be diminished. Opt for early morning or late evening application on a well-moistened soil, but avoid impending rainfall.

Here are some recipes and their properties for different plant-based brews:

  • Nettle Brew: Boosts plant growth and aids struggling plants.
  • Comfrey Brew: Balanced stimulant and fertilizer ideal for nutrient-deficient plants.
  • Horsetail Brew: Helps combat iron chlorosis and acts as a fungicide against various diseases.
  • Elderberry Brew: Stimulates growth for slower-growing plants.
  • Tomato Brew: Repels cabbage white butterflies, flea beetles, and leek moth, while also serving as a fertilizer.
  • Ivy Brew: Repels aphids, whiteflies, and mites.
  • Dandelion Brew: Fights fungal diseases in fruit trees and acts as a positive influence on fruit growth and quality.
  • Rhubarb Brew: Repels aphids and deters slugs.
  • Fern Brew: Acts as an insecticide against various aphids and is rich in phosphorus as a fertilizer.
  • Tansy Brew: Repels a wide range of insects.
  • Wormwood Brew: Acts as an insecticide against fruit worms, caterpillars, carrot and onion flies, and aphids.
  • Burdock Brew: Fights fungal diseases, serves as a fertilizer, and acts as a stimulant.

Contrary to popular belief, properly prepared fermented extracts do not produce unpleasant odors. With these plant-based brews, you can harness the power of nature to promote healthier plants and create a more sustainable gardening environment.

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I'm Jennifer. My hands are often covered in soil, and my heart is full of passion for nature. Through my writings, I share my personal gardening journeys, tips, and the joy of cultivating both plants and a community of fellow garden lovers. Every plant I grow adds a story to my life, and I love sharing those tales with my readers.