Formulas for Use Against Pests



Insecticidal Soap Spray Formula
2 tablespoons liquid soap
1 quart water (1L)

Combine ingredients in a bucket, mix, then transfer to a spray
bottle as needed.


Note: Natural soap is tolerated by plants better than detergent (which may have other ingredients such as surfactants, enzymes and softeners added). Buy a liquid soap and not a detergent. Health food stores supply liquid soaps.


Formula 1 for Tobacco Spray and Usage


Add 50grams of tobacco to 2 ltrs of boiled water to make stock concentrate. Leave to sit for 12 hours to cool. Filter the mixture through cheesecloth and store in a tightly sealed bottle. Add 1-1 1/2 tablespoons of this concentrate to 1L with 2.5ml of Polysorbate 20 (Tween 20). For leaf pests, spray leaves thoroughly, paying special attention to the undersides. Tobacco spray works by contact action only, so proper coverage of all plant parts is essential for control.


You will need to spray every 3-4 days for a couple of weeks to totally eradicate twospotted spider mite. The tobacco spray will kill the adult spider mites but not the eggs, so as eggs hatch reapplication is required.


Nicotine is also effective against ground and soil pests, especially root aphids and fungus gnats (sciaridae), and on many leaf-chewing insects, such as aphids. For soil pests, pour the dilute mixture onto the soil in the area of the stem base and root zone. For leaf pests, spray thoroughly on both the undersides and tops of leaves. Spray when the lights are off and turn off exhaust fans for 6 hours.




Nicotine, derived from tobacco species, is one of the most toxic substances used in the garden. It is extremely fast acting, causing sever disruption and failure of the nervous system. In its pure form, Nicotine is easily absorbed through the eyes, skin and mucous membranes, and can be very dangerous.


Nicotine poisoning describes the symptoms of the toxic effects of consuming nicotine, which can potentially be deadly. Historically, most cases of nicotine poisoning have been the result of use of nicotine (nicotine sulfate) as an insecticide. Keep your body and limbs covered, and wear protective gloves when mixing and gloves, safety glasses, long sleeved shirt, long trousers and a safety mask when applying.


Tobacco Spray Formula 2


1 cup tobacco
1 gallon water (3.8 litres)

8 ml polysorbate 20 (Tween 20) or 3 teaspoons dishwashing soap



Soak the tobacco in the water for at least 24 hours, until the mixture resembles a dark tea. Strain and place in an airtight container. Add 8ml polysorbate 20 or 3 teaspoons of dishwashing soap and use as foliar in the same way as you would with tobacco formula 1. Remember that you will need to reapply this formula every few days for a couple of weeks.


Rosemary and Neem Oil Formula 1L for Spider Mite (TSSM)

20mls Rosemary Oil (100% pure)

10ml Neem Oil (70% Neem Oil)

1gram lauric acid

6 ml Polyglyceryl Oleate



Start with 750ml of warm distilled or RO water. Add each ingredient and shake.


Top up to 1L final volume shake and apply directly when lights are off, spraying both tops and undersides of leaves. Turn off exhaust fans for 6 hours after spraying. The spray works through contact action only, so proper coverage of all plant parts is essential for control. Spray as needed. It is most effective re spider mite when a follow up spray is applied after 7 days.


Note: This formula has been shown to have 100% efficiency against TSSM. However, it is important to note that as botanical sprays can cause phytotoxicity it is recommended that you test it first on a single plant before applying to the entire crop.



Rosemary oil is easy to source and can be readily purchased through health stores or online. Here’s just one link that may help. HYPERLINK “” (120mls/4 oz = 14.35)


Polyglyceryl Oleate is a distilled triyglycerol ester based on vegetable oleic acid and is an excellent emulsifier (enables water & oil to mix). It is used in the cosmetic industry and can be sourced relatively easily. For instance, a Google for it took me to HYPERLINK “”http: where 4.2floz/125ml can be purchased for $6.95.


lauric acid is inexpensive, has a long shelf-life, and is non-toxic and safe to handle. It is a white, powdery solid with a faint odor of bay oil or soap. It is mainly used for the production of soaps and cosmetics.


Full Spectrum Botanical Oil Spray 1L


3ml Rosemary Oil

1.5ml Peppermint Oil

3 ml Thyme Oil

3ml Clove Oil

2.5ml Soybean Oil

2ml pure Coconut Oil

5ml Potassium Oleate

2.5ml Tween 20 (polysorbate 20)


For treatment of spider mite and other pests. Mix all ingredients into 1.5L of water and apply directly. Works on contact action only so apply thoroughly to tops and undersides of leaves.


Note Again: Botanical sprays can cause phytotoxicity. It is recommended that you test first on a single plant before applying to the entire crop. Always spray when lights are off.




A typical formula is to soak three ounces of chopped or minced garlic in a covered container of mineral oil for a day. Then, slowly add a pint of lukewarm water in which a quarter ounce of pure soap has been dissolved in. Stir and let stand several hours, than strain. Use as a concentrate, adding between 20 to 100 parts water to one part concentrate.

Other recipes call for boiling the garlic or for grinding or juicing it. Some brewers add other spices to the basic formula. One recipe calls for one clove garlic, three cayenne peppers, one onion, a quarts ounce of pure soap, and sufficient water to blend. Let it sit for three or four days before using, and use one part concentrate to 20 parts water.


Rules to Applying Botanical and other Foliar Sprays

  1. Always apply when lights are off. Foliar spraying when lights are on can result in plant burning.
  2. Leave lights and fans off for 4-6 hours after spraying.
  3. Botanical sprays work by contact action only. Ensure that good coverage is obtained on undersides and topsides of leaves.
  4. Botanical sprays can cause phytotoxicity (burning etc) – for this reason always test on one plant first.

Foliar Sprays and Botrytis


Many foliar sprays actually prevent moulds as well as tackle pests. Just some examples, are Stylet-Oil and botanical sprays. This said…


In a few instances, some foliar sprays used during the bloom cycle (particularly in later bloom) can increase the risk of bud rot (eg. Botrytis). For this reason we’ll cover some simple preventative practices that will ensure your flowers remain fungi free after foliar applications.


Use of Silica to Combat Botrytis

Silicon (Si) is the second most common element on Earth after oxygen and is abundant in soils.


Silicon is abundant in all field grown plants, but it is not present in most hydroponic solutions.


In plants, silicon strengthens cell walls, improving plant strength, health, and productivity.


Silicon, deposited in cell walls of plants, has been found to improve heat and drought tolerance and increase resistance to insects and fungal infections. Silicon can help plants deal with toxic levels of manganese, iron, phosphorus and aluminium as well as zinc deficiency.


Thus, the beneficial effects of silicon (Si) are threefold: 1) it protects against insect and disease attack (Cherif et al. 1994; Winslow, 1992; Samuels, 1991), 2) it protects against toxicity of metals (Vlamis and Williams, 1967; Baylis et al. 1994), and 3) it benefits quality and yield of agricultural crops (Kathryn E Richmond et al, 2003).


Silica is excluded from hydroponic nutrient formulas because it has a high pH and is unable to remain soluble (hold/remain stable) in concentrated nutrient formulas.


Therefore, Si needs to be added to the nutrient tank as a separate element.


Silica and Fungi Suppression (eg. Botrytis)

Si has been shown in numerous studies to suppress fungal pathogens such as Botrytis. In a study by Adatia et al (1986) conducted on cucumbers grown in recirculating hydroponic systems it was shown that despite regular applications of fungicide, outbreaks of the fungal disease occurred on most of the mature leaves of low Si cucumber plants, while the high Si plants remained almost completely free of fungal pathogens. The conclusion to this study noted:




“The addition of Si could be beneficial to cucumbers grown in areas where the local water supply is low in this element, especially when grown in recirculating solution or in a medium low in Si, e.g. peat.”


[End Quote]

Further research by Shettyet al (2011) demonstrated that Si treatment reduced powdery mildew development by inducing host defense responses in plants.3

It is believed that silicon deposition at sites of fungal pathogen penetration may be a common component of the host-defense response in a variety of plant families.


Silicon is also deposited in the cell walls of roots where it acts as a barrier against invasion by parasites and pathogens.


For instance, potassium silicate has been shown to act as a preventative against Pythium ultimum.


Studies have found that soluble Si polymerizes quickly and that disease development is suppressed only if Si is present in soluble form (Samuels et al., 1991b). To minimize disease development, Si must be provided continuously in the nutrient feed in hydroponic systems.


Therefore, a continuous source of soluble silicon is very important to combat pathogens. This can be from constant feeding in hydroponics or from retention in the growing medium with soils or soilless mixes.


Organic Anti Fungicide Spray Formula


Potassium Benzoate 1L Concentrate

250g/L Potassium Benzoate as powder (purchase from food additive suppliers or at

5 g/L Borax (available at any supermarket)

1)    Add Potassium Benzoate to 600ml demineralised water

2)    Add Borax to water

3)    Stir thoroughly

4)    Top up to 1L

5)    Stir thoroughly again until all ingredients integrate completely


Note: Potassium Benzoate at 250g/L will not dissolve/integrate into 1L of water without the use of Borax. The final product will be a dense liquid.


USE: 10 – 20ml/L dilution as foliar spray to prevent botrytis. Apply as preventative once weekly.


Note: This product contains potassium and flowers love an extra dose of potassium. It leaves no bitter taste and is therefore ideal for Botrytis control in indoor crops. Do not apply in the last week (during the flush) unless there are signs of fungi.



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