Introduction: Homemade Natural Insecticide/repellent
I have a very beautiful urban garden for years now.
Originally aiming to show my kids the magic of seeds, it became one of my favorite hobby during the good days. I usually grow tomatoes, fresh aromatic herbs (sage, verbena, thyme), strawberries and of course flowers. I also had cucumbers and zucchinis but those plants are too big for my garden.
Even if I am living in an apartment and my garden is a Urban Balcony garden (with some I'bles in it) I have to use insecticides/repellent mainly to get rid of ants and aphids (or greenflies).
As I want all my "production" to be organic I have developed from what I have seen on the web and other sources an environmentally friendly insecticide and repellent which works quite well.
What you will need
- Water
- (olive) Oil
- Liquid organic household soap
- Fresh Mint
- Fresh Stinging nettle
- Garlic
- Boiler(ev.)
- Bottle
Usual quantities for such preparation are 1kg of leaves for 10 liters of water. Make your own calculations ;-)
In this I'ble, I had a 5 liter bucket which I filled with leaves for about 500gr. I did weight it previously and saw that this way of quantifying my leaves was right. I used much more nettle than mint because I love mint and prefer to use it for my mojitos!!
Why those ingredients?
The water is the base of our insecticide/repellent
Oil and Organic Household soap are wetting agents and help the mixture to stay longer on leaves. They are also generating a thin oily film on the plants and insects keeping them out of the leaves but firstly suffocating them. I preferably use Olive Oil because it is the best mix with organic household soap which are made out of... olive oil (at least here in France, this is the well-know "savon de marseille"). It is the "insecticide" part of our mixture. Good point (or bad, it depends): it is only active on small insects...
Fresh mint , garlic and stinging nettle have a repellent action on greenflies and ants. Good, that's what I have on my balcony.
Step 1: Make Your Own
Let's start to make our own!
Best is to use fresh water. If not available boil fresh water. This is to clean your water and help the dissolved chlorine to go out of your tap water.
Choose your plants as free of diseases and so.
Spread the mint leaves (a good handful), the (smashed) garlic (2 or 3) and the nettle (a good handful too) in the bucket. Chop them into small pieces. Add the water.
Wait for at least on day. It is the required time for the essential oil and active molecules to go from the leaves to the water.
You need to use cold water because hot water can arm active molecules. Your water should be free of chlorine as much as possible as chlorine kills bacteria and fungi (good or bad).
After one day, filter the mixture and keep the infusion.
For my 5 liters of infusion, I add 10 ml of organic household soap and 2 spoon of oil. Mix it avoiding to make too much foam.
Step 2: Using Your Spray
First be sure that your infusion is neither hot nor too cold. Hot, it would kill your plants, cold, it would shock them.
Put the mixture in a disposer and spray it.
Directly on your plants or on insects ways.
Take care to spray it under the leaves (to tackle greenflies) and not during high sun hours. Prefer the late afternoon.
Of course, if your need is more repellent then you can only make the infusion part of recipe, same with oil and soap if you need an insecticide....
You're done!
Thanks for reading, thanks for sharing!
If it happens that you make it, please let me know if it has worked for you! If you liked it, please share it and vote for this I'ble ;-)

Participated in the
Gardening Contest 2017
4 Comments
5 years ago
Menthol 1g an L, 1g Bitterex an L, cinnamon extract from 70 percent ethanol and soap would repel cats, dogs, other animals with bad taste and cats and dogs don't really like Mint smell with cinnamon.
The cinnamon-menthol prep must be either Soxhlet extracted or Refluxed distillation tho. It could be added to cold soluton and filtered off later (this takes a week) with shaking if distillation is not used.
5 years ago
I was thinking coffee (Instant) or Decaf Instant that 5 g in an L with 1 g per 1000 ml of Bitterex chemical as a repellant. The Bitterex at 500 mg (half of that) is extremely bitter and if it gets on you (you will not be eating for a few days-Wear gloves when making it and applying it.) The bitterex biodegrades.
The only issue is coffee which can be toxic. Bitterex can attract cats too. Yes the bitterex could be refluxed (distilled in ethanol, mint (Menthol), etc. 3 g of Menthol in 1 L of 70 percent ethanol instead of coffee could with bitterex repel lots of animals and insects (tastes bad and cats do not like mint smelling chemicals either.)
I may do an Instructable with bitterex, 70 percent ethanol (which evaporates off leaving bitterex and menthol) and menthol to repel insects and animals.
6 years ago
Thanks! Let me know if it works. If you have lots of mites on large plants such as trees, you might be better at using manure or decoction. See this other I'bles I have made on this topic.
https://www.instructables.com/id/Organic-Care-of-Yo...
I have personally used the Fern manure with great results on both mites and aphids.
If you have aphids (I don't know what mites means in english because it is a quite general work in french), try to look after the ants and cut their way to your trees. They love aphids "honey" and thus help them to spread.
6 years ago
Thanks for the recipe and instructions. I'll try it to kill off the mites I have on my fruit trees.