By Marie-Helene Blackmore
Affordable, easy to apply and eco-friendly, Black Soap and Savon de Marseille (Marseilles Soap) come in handy at the first appearance of pests or diseases due to their manifold qualities: insecticide, wetting agent, emulsifier and bactericide. Effective but gentle, both soaps may be used on multiple sensitive plants and seedlings with no adverse reactions. They are an excellent adjuvant for enhancing the adhesiveness and penetration of preparations for the treatment of plants, thereby allowing for better assimilation and less susceptibility to leaching. Their adhesive and bactericidal properties reinforce the preventive action. They are also an ideal emulsifier, assisting with the dispersion of oil-based solutions in water. Made from a base of vegetable oils, Black Soap and Marseilles Soap are completely biodegradable.
Black Soap Available online in Savons d’ailleurs eBoutique, Marius Fabre Savon noir – Liquid Black Soap with Olive Oil should be diluted in warm water just before use.
Savon de Marseille Gentler than Black Soap, genuine Savon de Marseille such as Le Sérail – Antique Savon de Marseille Olive Oil is essentially use for the control of aphids. Also available online in Savons d’ailleurs eBoutique.
Aphids, caterpillars and other insects
1/ Recipe with Black Soap: Whisk three tablespoonfuls of liquid Black Soap in one litre of hot water, mixing well. Allow to cool and pour into a spray bottle. Carefully spray over the upper and lower surfaces of all the leaves for optimal coverage. Spray rather in the morning or the evening and never in the heat of the sun or when it is raining. Repeat, if necessary, two or three days later.
2/ Recipe with Savon de Marseille: Shave a cube of Savon de Marseille on a cheese grater with large holes. Mix a handful of the shavings in one litre of hot water, stirring until they are all completely dissolved. Allow to cool and pour into a spray bottle.
When should it be used? As required, throughout the year.
How often? Where there is a substantial presence of aphids with a rapid life cycle and high reproductive rate, treatment once a week may be necessary.
Variations - Add a few drops of essential oil of lavender which acts as an insect repellent, or add 1 tbsp of canola oil, to deal with the most resistant insects.
Some parasites like aphids will cause a type of black mould to form: sooty mould. It grows on the leaves, makes them sticky and gradually asphyxiates them, blocking photosynthesis and causing them to drop off. No need for a specific product to get rid of it, Black Soap does the trick.
Recipe: In a small bowl dilute three tbsp of Black Soap with five litres of warm water. Remove the blackish deposit using a small sponge. It will come off easily.
Black spot and other fungal diseases
Recipe with Bicarbonate of Soda: Strictly speaking, bicarbonate of soda is not a fungicide because it does not kill fungi in the same way as conventional treatment does, but its basic pH level blocks fungal growth. Never exceed the dose of 1 to 2 tsp per litre of water as you may burn the foliage. The mixture will adhere better if a little oil is added; in this very simple recipe, Black Soap serves as a wetting agent and already contains olive oil. For five litres of this solution, begin by mixing in a bowl 5 tsp of bicarbonate of soda with 3 tbsp of Black Soap. Add some warm water and beat with a whisk until all is properly dissolved. Pour this solution into a sprayer and top up with the volume of water required.
Application - Spray in the evening and especially at the first manifestation of disease. Continue once a week during stretches when fungal diseases are likely to develop on dry leaves, for example, after storms. Three or four sprayings will generally be enough.
ALL-ROUND ECO-FRIENDLY PESTICIDE
1/ Garlic Oil Macerate Recipe: This preparation is based on a maceration of garlic in oil. Easy to prepare, it is primarily used as an insecticide, an insect repellent and a fungicide. Chop up 100 grams of garlic with its skin on. Add 3 tbsp of olive oil. Cover and leave to macerate for twenty-four hours.
Filter through a fine strainer then squeeze the pulp to extract the maximum amount of active ingredients. Add 1 tbsp of Black Soap and beat with a whisk, then pour in one litre of water. This macerate can be kept in a cool place away from the light for about three weeks.
Application - Dilute to a 5% solution and spray in the evening (repeat regularly).
Use as an insecticide and insect repellent against aphids, mites, onion maggots and Colorado beetles. Use as a fungicide for fungal diseases such as rust, botrytis, peach leaf curl, etc.
2/ Chilli Oil Macerate Recipe: This preparation is based on a maceration of chillies in oil. Easy to prepare, it is primarily used as an insecticide, an insect repellent and a fungicide. Mix 1 tsp of hot chilli powder in 1 tbsp of olive oil. Whisk until the chilli is thoroughly mixed with the oil. Leave to macerate for a few hours and add 1 tbsp of Black Soap. Gradually dilute with 250ml of water to obtain a total emulsion. Pour into a spray bottle and use immediately.
Alternative Recipe with Whole Chillies: Wear gloves when preparing this as capsaicin is highly irritating to the skin and mucosal tissue. Soak a handful of chopped hot chillies in one litre of water for twenty-four hours. Filter through a fine cloth or a coffee filter, squeezing a little. Add 1 tbsp of Black Soap. Pour into a spray bottle, shake and spray.
Application - Used undiluted and as a spray, this mixture serves as an insecticide or insect repellent. It rids plants of aphids, caterpillars, mites, flea beetles, etc.
How often should it be used? During periods of proliferation, regular treatments are necessary every 8 to 10 days.
* Economic tip * When you wash your floors with a solution of Black Soap, do not throw the soapy mix out: rather recycle it on the undesirables in your garden.
Photo: ©123rf Ababaka