Organic Pesticide and Fungicide Spray





Introduction: Organic Pesticide and Fungicide Spray

This instructable will teach you how to make an all-in-one pesticide and fungicide spray that works great for indoor and outdoor plants. My boyfriend recently got into the IPM (integrated pest management) approach to gardening, so he's been spending a good amount of time learning about natural ways to combat pests and fungus on our plants and I've been learning along with him!

If you're looking to learn about IPM and other foliar sprays you can make, I highly recommend checking out BuildASoil - they have an amazing blog and store and offer fantastic phone support for any problems you run into. My boyfriend's spent a good deal of time on the phone getting advice from them - they're always top notch!

This foliar spray utilizes neem oil, potassium silicate, aloe vera and various essential oils to combat many types of pests and fungi. It can be applied once a week to control any issues that come up with your garden!

The amount of foliar spray this recipe makes should be able to completely saturate at least three large plants - we used it on two three foot tall trees (avocado and lemon) and a few succulents.

Step 1: What You'll Need


  • 1/4 gallon (4 cups) warm water
  • 1/4 tablespoon neem oil
  • 1/2 teaspoon 7.8% potassium silicate solution
  • 1/4 oz (1.5 teaspoons or 150 drops total) assorted essential oils - we're using an even blend of ginger, rosemary, clove, peppermint and eucalyptus
  • 1 tablespoon aloe vera juice (we have a powder we add to water to make this)


All ingredients listed above can be found through BuildASoil and Amazon. BuildASoil offers a complete IPM kit that's great if you're just starting out.

Check out this report from BuildASoil to find out how neem oil, potassium silicate, essential oils and aloe vera work together to create an effective foliar spray. The report also includes links to studies so you can learn more about each ingredient.

Here's a basic summary of why we're using each ingredient:

  • Neem Oil contains a chemical compound called azadirachtin. This compound is toxic to many insects, and acts as a feeding inhibitor and a growth disruptor. It is a natural insecticide that is biodegradable.
  • Aloe vera acts as a source of salicylic acid. Salicylic acid is necessary for activating a plant's immune system to respond to threats.
  • Potassium silicate is a natural fungicide, insecticide and miticide.
  • The essential oils used in the foliar spray have a variety of anti-fungal and pesticide properties. Click through to the report above to learn what other oils you can use.

Step 2: First Mixing

You'll want to take 1-2 cups of warm water (75-85 F) and put it in a large jar.

Add the aloe juice to the warm water and shake to combine. It should be nice an clear once mixed.

Now add in the neem oil and potassium silicate. (You may need to warm the neem oil jar up in some water to make it fluid if it's cold where you are!)

Step 3: Shake to Emulsify

Shake shake and shake some more.

You want to entirely emulsify the mix. It should be nice and creamy looking with no oil floating on top.

If you're having issues with mixing, check out this awesome video by Jeremy from BuildASoil - he's got lots of advice for getting it right:

Step 4: Pour Into the Sprayer + Add the Rest of the Water

Once the mix is emulsified, pour it into the sprayer and add the rest of the warm water. Remember you need four cups total.

Shake again.

Step 5: Add the Essential Oils

Now you'll want to add in your essential oils. You need about 1.5 teaspoons total. We used a little over 1/4 teaspoon per each oil: ginger, rosemary, clove, peppermint and eucalyptus.

Shake super vigorously again to keep things emulsified.

Step 6: Spray!

Pictured above: Limón! He's a lemon tree I grew from seed and Tyler has been keeping him alive and happy for over 2 1/2 years now. Yay for Tyler having a major green thumb!

You will want to only apply this spray out of direct light. Essential oils can cause burns on the leaves if left in direct light. It's also a good idea to wear a mask if you have any respiratory issues!

For inside plants, apply the spray with lights out.

For outside plants, only apply late in the day so there's no direct sunlight beating down on the plants.

Try to apply whenever you'll have at least several hours of darkness. For example, don't apply it to outside plants in the morning - the midday sun could cause burns even thought it was applied hours before.

Completely saturate the leaves (both tops and bottoms!) with the spray until the plant is drooping a bit. Try to keep your focus on the leaves and avoid spraying directly onto the soil.

And there you go! I hope this spray will be useful for you guys - it's been fantastic for us!



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Are any of these ingredients toxic to bees and butterflies? I'm hoping to encourage beneficial insects...

neem oil and bee nogo

Thankfully, in the reading I've done, I haven't seen any studies suggest the oils would be toxic to bees or butterflies. Some beekeepers actually use essential oils in their hives to try to combat mite infestations, which is pretty neat.

I've actually read about certain oils attracting both bees and butterflies, too! I know they like lavender and sage. :)

The -only- problem I would see with this, is the use of it on any of the Milkweeds (Asclepias tuberosa, and Asclepias syriaca - about 140 species) which are the only plant that the Monarch (Butterfly) Caterpillar can eat. They need these milkweeds to survive. As long as people don't use it on the milkweeds - I see no other problem with it at all!

Thats the cool thing about the active ingredient in neem oil, it only effects the bugs that eat the plant tissue making them think they are full so they happily starve! I was thinking we could water it down a bit and use it as diet tea! Back to more serious though this won't effect the beneficials especially if you use it at night as suggested. The bees etc will be sleeping and the mites etc will be about their work. One thing though there are several of the bugs you are targeting that spend their infancy in the top layer of soil so getting it on the soil around the bottom can help with thrips and other hard to get little guys.

Look up " Bordeaux mixture " and save yourself time and money

While Bordeaux is good for fungus and such, it's not real effective on the bad insects.

Hi, I used an oil-based insecticide on my kale and it killed one of my varietals. Test on a single leaf first to check!


I like it . Been using a solution made of tobacco and cayenne pepper , works , but leaves an aftertaste that encourages me to go in a new direction ,especially since starting to grow indoors ( No deer in the house) .