How To Make A Natural Insecticide From Rhubarb Leaves

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You might enjoy using rhubarb in pies and other foods. Most of us never think about trying to make insecticide from rhubarb leaves. I know I didn’t.

We know the Rhubarb stalks and stems are perfectly edible. On the other hand, the leaves are not.

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How To Make Insecticide From Rhubarb Leaves

If you grow a garden, you can use the leaves of the rhubarb plant to act as a natural insecticide. Here’s a short guide that will help you create this helpful concoction.

Are Rhubarb Leaves Poisonous?

The species Rheum x hybridum is commonly grown as an edible vegetable across Europe and North America. 

Although rhubarb is botanically a vegetable, it’s classified as a fruit in the United States. It has long fibrous stalks that range from dark red to pale green.  

These are often chopped and cooked with sugar due to their very sour taste. Meanwhile, its large dark green leaves look a bit like spinach and are not usually eaten due to fears about them being poisonous or inedible.

In the kidneys, this can lead to the formation of kidney stones and, eventually, kidney failure. Mild rhubarb leaf poisoning symptoms include vomiting and diarrhea that resolve within a few hours. 

More serious oxalate toxicity causes sore throat, difficulty swallowing, nausea, vomiting (sometimes including blood), diarrhea, and abdominal pain.

Why Do Rhubarb Leaves Work To Repel Insects and Pests?

Rhubarb leaves contain oxalic acid, which can not only stop your heart but also make a great natural pesticide for leaf-eating insects.

If plant lice (aphids) or other insect pests attack your plants, the acid in the rhubarb leaf pesticide should work to suffocate and otherwise disturb them. Over time, you won’t need to worry about the bugs.

How To Make Pesticide From Rhubarb Leaves

The first thing you must do to make an insecticide solution: collect rhubarb leaves. Of course, if you grow the plant yourself, you can use your own leaves. 

If not, you can head to the supermarket and buy some rhubarb, which typically still has the green leaves attached.

Rhubarb Leaf Insecticide Recipe

Cut the stems off the leaves to use in cooking or other activities, and keep the leaves for your insecticide.

Once you’ve your rhubarb leaves, you’ll need to boil them in water. Try to keep a 1:3 ratio between the leaves and water.

For instance, if you’ve got a cup of rhubarb leaves, use three cups of water. Boil the leaves in a pot for about half an hour, and allow to cool.

Next, using a strainer, remove all the leaves from the pot. Add a little liquid dish detergent, and then pour the solution into a spray bottle. That’s all there is to it!

Once you’ve made the natural insecticide plant spray, begin spraying the various plants in your yard or garden. 

You might want to do this spraying in mid-morning or mid-afternoon so that it doesn’t evaporate too quickly. Over time, you should start to see that insects find your plants less attractive.

NOTE: Always TEST the rhubarb spray in a small area to make sure the plant will not suffer any damage.

How Long Can You Keep The Rhubarb Leaves Insecticide Spray?

Ideally, you’ll want to use the entire rhubarb pest control solution within a day or two. Keep in mind that the longer you wait, the less effective it may become.

Should You Use The Spray On Plants Grown For Food?

Otherwise, there are plenty of fantastic ways to put these large greens to good use.

While insecticide made from rhubarb leaves can be effective against insects on all different kinds of plants, you may want to exercise caution and avoid spraying the solution on plants you plan to eat.

Now that you’ve got more information about making and using a natural insecticide from rhubarb leaves, cook up a batch. You should soon see fewer bugs and more beautiful plants.

7 Surprisingly Brilliant Uses For Rhubarb Leaves

Weed Barrier and Mulch

Some weeds are so tenacious that no matter how many times you pull them up, they keep coming back again and again.

Laying down a weed barrier, like cardboard or newspaper, and topping it with mulch really does help lessen the Sisyphean task of keeping the garden beds clear of weeds.

Rhubarb’s large and heart-shaped leaves lend themselves well as a weed barrier, too.

Garden Stepping Stones

Leaf casting is a marvelous way to create a natural look for your outdoor spaces.

Prominently veined leaves make for the most beautiful castings. Hosta, squash, elephant ear, coleus, and rhubarb are all good candidates for this project.

Set the foliage down, veiny side up, on a flat spot, and apply a thick layer of concrete all over the leaf surface.

To ensure the casting is strong, use chicken wire or hardware cloth between layers of concrete. This will act as rebar and ensure the stepping stones last a long time.

Bird Bath

This same technique can be used to make the perfect water-holding bird bath.

Instead of working on a flat surface, sand is mounded up, and the upside-down leaf is placed on top. As the concrete dries, it will create a bowl shape for the leaf cast.

A wire brush can be used around the leaf edges to shape and finish the final product. Add a coat of paint or leave it plain.

Cleaning Solution

Oxalic acid is a natural substance found in many plants, including leafy greens, fruits, vegetables, nuts, seeds, and cocoa.

The oxalic acid content in the rhubarb leaf spray may be too high and could make you or a family member ill. But the oxalic acid in rhubarb leaves decomposes quickly and won’t harm the microbes working the compost heap.  

As a non-abrasive and bleach-free powder, it is safe to use on numerous surfaces like stainless steel, ceramic, porcelain, fiberglass, chrome, copper, aluminum, brass, and more. 

Effective for cleaning, polishing, bleaching, and rust removal, oxalic acid is also excellent for lifting stains from wood without altering the wood’s natural color.

While it may not be as potent as store-bought cleansing products, oxalic acid is water soluble and can be extracted from fresh rhubarb leaves by boiling them in a pot of water for about 30 minutes.

Organic rhubarb insecticide

Rhubarb plants, once established, are fairly easygoing and trouble-free.

Few pests seem to bother the plant. Most commonly, slugs and snails, rhubarb curculio, and common stalk borer are the ones to watch out for – but these never seem to do enough damage to actually impact the quality of the harvest.

It is thought that the high level of oxalic acid in rhubarb leaves is what makes them so unappealing to many foliage-chewing insects.

To make an insecticidal spray, boil rhubarb leaves in water for 20 to 30 minutes. Allow it to cool, strain out the leaves, and transfer to a spray bottle. Add a couple of drops of liquid dish soap before spritzing your plants.

Natural Dye

A rich source of dye colors for natural fabrics like wool can be found in the garden. The roots, berries, bark, leaves, and flowers of diverse plants may produce essentially every color of the rainbow.

Rhubarb leaves can be used to make a dye bath by boiling them in a big stock pot. The color of the dish will depend on how many leaves you use and how long you simmer it.

A softer golden color can be achieved by using fewer leaves and a shorter cooking time. Before dropping the skein of yarn in, 2.5-gallon bags of rhubarb leaves were cooked three to four times to extract color.


Last but not least, rhubarb leaves are a good source of nitrogen and can always be tossed into the compost pile.

This might seem terribly counterintuitive since the leaves are toxic!

But the oxalic acid in rhubarb leaves decomposes quickly and won’t harm the microbes working the compost heap.

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