DIY Pesticides get a bad wrap for being less than stellar. But over the years I’ve realized one thing that all of them are missing and that is science. In this post, we are going to break down the DIY pesticides lurking around the internet and find the best recipes that will work for you. The best way to do this is by adding a flare of microbiology and a side of chemistry. So, put your lab coat on and grab your notebook- because we are about to dive deep.
What is a Pesticide?
The term pesticide is broad; it encompasses everything from insecticides, herbicides, fungicides & everything in between. When we talk about DIY pesticides, we can end up with multipurpose control and the fact it is not engineered to attack a specific problem. This is important to remember because it also means DIY pesticides can be harmful if over-applied to our plants.
Pesticides can be further broken down into application types. Application types can range from foliar sprays to soil amendments. Depending on what critter you are fighting some may work better than others. So, let's jump into the DIY world of pesticides starting with the soil and working our way up into the foliage.
Moldy Soil Prevention
Soil mold is common when starting seedlings. This is concerning because some molds can cause something called dampening. Dampening is a broad term that refers to a host of bacteria and fungi that ultimately results in seedling death. Luckily, there is a DIY pesticide solution for this problem and it’s called cinnamon.
Seriously, the spice you have in the cupboard is one the strongest antibacterial & antifungal solutions for soil molds. The application is simple. All you do is sprinkle the soil surface similar to how you like your lattes. This can be done before the mold is present or once you notice mold appearing on the surface. Another quick solution is to lift the germination dome off the top of the seedling tray for a few hours to allow for some airflow.
Insects: Soapy Water & Hot Peppers
This is a double whammy fix that works well. Remember how I mentioned some DIY Pesticides have a kill-all attitude when it comes to pests? This combo is the holy grail of pest control, especially for indoor plants. The recipe is simple. All you need is a spray bottle, 6 drops of dish soap & 2 tablespoons of any pepper you choose. Some suggestions are: Red Pepper Flakes, Chilli Peppers, Dill, Ginger, Paprika, Black Pepper, Garlic (these you can stick the whole peeled clove into the soil)
The theory behind the madness is simple insects cannot survive in areas covered with capsaicin. Capsaicin is found in all the herbs listed above and is what causes “the burn” when you rub your eyes, skin or mouth after touching hot pepper seeds. Needless to say, that irritation is passed onto the insect and they enjoy it about as much as you do.
The soap also plays a major role in pest control as well. Soap will help to dry out any larvae on the leaves. And it will be able to help the pepper of your choosing stay in place.
The best way to apply this is manually. Simply spray down the leaves both top/bottom and the stem. From there take a washcloth and gently remove the excess water. The process of wiping off the leaves will help remove any dust build-up, fungal spores & bacterial colonies that may harm the plant. It will also allow for better photosynthesis & ultimately a healthier plant. You can use this mixture as a preventative once a month or during an active pest invasion once a week.
Slugs, Snail & Beer
This was a must-add DIY because beer is a must-have tool in a gardener’s arsenal. This trick is for slug & snail prevention and it works a little too well. All you do is take a pie plate and place it in the problem area with an inch or so of beer. Turns out slugs and snails enjoy visiting beer gardens; the only issue is they rarely leave the bar. All joking aside it does work, but you will need to dump the mini murder scene every day and place a fresh trap until the issue is resolved.
Weeds & Vinegar
Vinegar is the only herbicide to make the list and that is because it's really the only herbicide you need to use. Word of warning: do not use vinegar near plants you want to keep around, it shows no mercy. This is a simple DIY herbicide; full strength sprays or pours it right into the weed in question. Within a few hours, the weed will no longer be an issue. I commonly use this on sidewalks & brick areas because it's pet & child friendly