Natural fungicides and insecticides for your plants

There’s nothing more disheartening than watching your plants that you’ve nurtured and cared for succumb to a plague of little suckers or dissolve under a blanket of fur.

The first step to keeping your plants happy and healthy is to ensure their environment isn’t a haven for unwanted organisms. Much of this has to do with encouraging natural predators into your growing space. Make ladybirds happy and you won’t have an aphid problem. Keep the ground beetles coming and they’ll help take care of slugs. Keep your soil healthy and the nematodes will help out. Encourage everything from dragonflies to bats, and they’ll all help with pest control. I will write something further about natural predators in another post, but for this post, let’s concentrate on what to do to resolve a problem once you have it.

The second thing to remember is that bugs are a normal part of a garden, many bugs are beneficial or neutral to your plant, and a small amount of even the plant sucking varieties will do your plants no harm and will provide food for their predators. On the other hand, you don’t want an infestation so keep an eye out for particular problem bugs and use one of the methods below to control them, remembering that you are controlling not completely eliminating them.

Many of these remedies involve spraying your plants. When doing this first test spray a small portion of the plant or leaf and wait overnight to see how it fares. Always spray your plants early in the morning or in the evening to avoid burning them or reacting badly because of the heat. Do not add more spray or increase the strength if you are not getting good results as this could harm your plant or drive away predator bugs that eat the bad bugs. Experiment with different repellents to see which one works best for your plants.


Here are some of the common plant problems you may encounter:


If you have an attack of powdery mildew on your leaves, or maybe your seedlings are surrounded by hairy mold, one of the best things you can use is cinnamon. Cinnamon is a fantastic fungicide whilst also being great for your plants. You can also use it as a rooting hormone, helping to heal plant wounds, and even deterring ants. It can be applied directly to the soil or plant, or made into a liquid for spraying leaves. Simply add cinnamon to water and allow it to stew overnight, then strain and decant into a spray bottle.

For peach leaf curl: remove affected leaves (even dropped ones). Give the tree extra feed to recover (compost tea, spent coffee ground for nitrogen, epson salts for magnesium). Spray the entire tree with oregano oil (6-7 ml oregano oil diluted in16 0z of water ) at least twice a year (once before buds develop).

Aphids and other soft-bodied pests

Aphids, mites, mealybugs, whitefly, leafhoppers, the list goes on and on.. all these little pests suck the life from your plants. There are a few natural remedies you can try for these buggers, mainly involving using the natural spray remedies listed below, ensuring to get the underside of the leaves. My favourite that has worked well for all the pest problems I’ve had so far is the garlic/onion/chilli spray.

You can also make your own sticky trap for aphids by coating something with yellow with vaseline; an upturned plastic cup on a stick does this well.

Worms and Caterpillers

To deal with these little leaf munchers, simply sprinkle baking soda on your brassicas.

The hornworm in particular can be a challenge, but sprinkling with cornstarch can help to suffocate them and make removing them for disposal an easier job.

To curb attacks, try making a mash of marigold leaves and flowers, and soak in water for 24 hours. Strain the solids, and add another 1.5 quarts of water plus a drop of liquid castille soap before spraying.


I’ve written a whole post on slugs that you can find here. My favorite methods are surrounding your patch with copper, in combination with beer traps.


Basic Oil and Soap

Mix 1 tbsp of soap and 2 tbsp of oil with 2 cups of water for a basic insecticidal spray for plants.

For added insecticidal power it with one of the other remedies listed below.
Add a spoon of baking soda for added fungicidal repellant.

Spicy does it

Garlic, onion, chilli, and horseradish are all natural repellants.

Make a spray by mixing one or a combination of these (crushed) with water. Leave to brew overnight, then strain and spray on the plant as an insecticidal.


Another insecticidal remedy is to simply boil rhubarb leaves in water for 20 minutes, and when cool strain into a spray bottle.

Hydrogen Peroxide

Mix 8 ounces of Hydrogen Peroxide, a gallon of water and 8 ounces of sugar together for a long lasting formula to spray on plants and leaves that can act as both an insecticidal and antifungal. Be sparing with this one, I’ve had some experience of leaves being unhappy with it.


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