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Garlic water sprayed onto the orchid’s potting medium is a one of topics that slowly had me in total awe. I started my research as to how garlic worked on plants and in the garden, and that lead to a whole list of the benefits of garlic.

Immediately putting up a mental fence, I thought, “This can’t be true. I bet most of what I’m reading are myths that have been around for so long, they have now become true.” Well, I was wrong. In this article, I am going to go over what happens to your orchids when you add garlic to your water.

Garlic is a natural deterrent in your orchid pot when it comes to spider mites, thrips, and aphids due to its high levels of sulfur. When garlic is applied to your orchid, it will aid in chlorophyll formation, protein synthesis, and the formation of 21 amino acids. Garlic acts as a natural fungicide in the orchid potting media, preventing the spread of spores. If used in a strong concentration, garlic water will hinder your orchid growth, so use it sparingly.

Let’s look at those one by one. By the end of this article, I hope you’re as sold on using garlic water as I am. As I researched each point in what seemed to be myths around the use of garlic in orchid care, I slowly converted to the efficacy of its use.

Just a note of advice, I find that a lot of orchid growers are reluctant o the use of fertilizer and fertilizer supplements and often I get the comments to leave the kitchen out of the orchid pot.

I would like to kindly respond, saying to these growers that not all fertilizer products are available in some countries. Other times, it’s the choice of the individual grower to use natural products instead of chemically induced ones. If garlic is not your thing, that’s perfectly fine. But I do ask that you respect those who do use it.
Garlic Clove and An Orchid
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In popular culture, garlic (Allium sativum L.) is used to repel Dracula and keep other vampires at large. Even though that “deterrent use of garlic” is a fantasy, it’s suspected that garlic, due to its strong taste and smell, will repel most garden critters. That theory was put to test and proven to be true. The high concentrations of sulfur were the culprit for such a pungent smell.

Little garden critters that will inhabit the orchid pot are also not too fond of the high sulfur content (along with the tangy smell) and will avoid the plant in its’ entirety. Although the list of critters that garlic repels is highly inflated due to myth, there is only proof of experiments showing positive results of garlic fending off aphids, diamondback moths, and spider mites.

If you have an infestation of aphids or spider mites in your orchid pot, garlic water is a good way to keep that infestation down. It will not kill these pests, so another method is required to reduce the mite population in your orchid media, but the garlic water can keep them away once they are gone.

In this sense, garlic is approved as a natural deterrent when it comes to small pests and insects. (Source)

Not only does garlic work as a deterrent, in 1992, the United Sates Environmental Protection Agency (US-EPA) approved garlic as a natural pesticide. I couldn’t din evidence that it actually killed the pests, but I won’t argue with them. Their evidenced proved that most pesticides (they listed 4) have garlic in the components. The main pests listed were birds and insects. (Source)


This was also on the list of items I set out to look for proof. It’s pretty hard to kill a fungus because they like to feed on bacteria. So where one is present, the other will soon come to join the party.

I usually use Physan 20 (which you can see here – Affiliate Link) to kill fungus and bacteria. In some countries, Physan 20 isn’t available, so garlic is a great way to keep the fungus population down to a minimum.

In this study (Source) called “Garlic, from Remedy to Stimulant: Evaluation of Antifungal Potential Reveals Diversity in Phytoalexin Allicin Content among Garlic Cultivars” published August 2019, it was proven that garlic inhibits the spores, thus preventing the spread of fungi. This qualifies garlic water to be a fungicide.

If that evidence wasn’t enough, in this study, the authors stated that garlic “offers a very attractive option to consider as bio-stimulator or inducer for enhanced production and significant protection against variety of fungal disorders.” (Source)

Since fungus is a huge problem once root rot sets in, the orchid will benefit from having the potting media soak in a solution of garlic water or at least the top of the media sprayed.
Garlic and Orchids
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By now you might be wondering what garlic does to your orchid. The smell and taste of garlic are due to the extremely high percentages of sulfur in the garlic’s cells. Along with sulfur, garlic does contain Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca) and Manganese (Mn). All of these are essential for orchid growth. Since their concentrations are not as high as sulfur, I’ll just focus on the sulfur.

Sulfur is considered to be more important as a essential nutrient as the years go by. You probably know by now that the 3 main essential major elements in orchid care are included in the NPK ratio. There is more information about that in this article I wrote about NPK. (LINK)

Sulfur, although not a primary element, is considered to be a secondary element along with Calcium(C) and Magnesium (Mg). With more and more studies being conducted through the years, it has been proven that sulfur is one of those essential elements that has been overlooked for too long.

Sulfur works in combination with so many other elements, that it is a building block to form most all essential chemical reactions necessary for your orchid’s life. According to Sulfur – the 4th Major Nutrient, sulfur “helps develop and activate certain enzymes and vitamins and is a structural component of two of the 21 amino acids that form protein.” Along with the aid of nitrogen, sulfur will build protein chains and help create chlorophyll.

It’s too easy to overlook the importance of sulfur because although it’s almost impossible to pinpoint one major contribution to your orchid, it is used in so many other chemical reactions as a major element which couldn’t be possible without its presence. (Source)

In another study, the effects of root growth was positively affected by the use of garlic water. The roots—although it was a tomato plant, not an orchid—showed visible signs of better growth. The not so visible signs were analyzed, proving that garlic water promoted “cell division, phytohormones, and the expression levels of expansin genes”. (Source)


Not all garlic is great in your orchid pot. Too much garlic can be harmful and cause the chemicals to stop responding the way they normally would. Since garlic has an overpowering presence of sulfur, this element may want to compete with others inside your orchid’s cells.

This competition, or how one plant changes the effects of other plants near it, is called allelopathy. In some senses, the two plants will work in symphony and create stronger cells that are more resistant to pests and diseases. They work together, aiding each other. In other circumstances, the growth of 2 plants together will fight for their “time in the sun” and end up killing each other.

This is why it’s important that you know what you are doing when planting 2 orchids in the same pot. They can fight each other for nutrients and usually the orchid with the most prominent roots (as in in size and thickness) will win, leaving the struggling smaller orchid out to dry. I wrote a whole article about what orchids you can plant together, which you can read here (LINK).

How does this information transfer to your orchid care? It’s fine to use garlic water to spray your orchid and even soak the pot in this solution, if you don’t use it all the time.

The high proportions of garlic will start to damage the lipids, which in turn hindered the seedling growth. Also, the new seeds were not formed properly. In their words, “at higher concentrations, it might cause lipid peroxidation and membrane damage which temper the growth of…seedlings.” (Source)


Even though this part is not important to orchid care, I have discovered that most people who grow orchids also have other plants—some of those include vegetables. If you want to take this information about garlic and orchids, and transfer it to your garden, I highly suggest otherwise.

Remember the relationship between garlic and orchids in the previous paragraph? That allelopathy combination? Well, in some plants, garlic can hinder their growth and deter their cell propagation in a negative way. The plants that you shouldn’t grow next to garlic (not only use the garlic water but avoid planting in the same patch) are asparagus, peas, beans, sage, parsley and strawberries.

The same study that showed that the pests had declined 52% with the use of garlic water also showed that the actual growth of the strawberry decreased too. This was proven with all the vegetables, fruits and plants above. Garlic deters the little pests, but in some cases, it also deters the actual plant production.

For orchid care, this means that the garlic water needs to be used sparingly. You can mist the media and leaves to use it as a preventive measure one a month, but I’d advise against using it too much.


I left the best for last: how to make garlic water. Not only did I do this on purpose, but I had a hard time finding a consensus of what recipe to use. Some said to use one clove, others used 4. Some boiled the garlic, other crushed it. Other people just soaked the whole clove in water.

Below I listed just one of the many garlic water recipes, so adapt it as you like and find out what works for you.

Using a diluted rather than a more concentrated form of this garlic water is the best path to protect your orchid from an overpowering proportion of sulfur.
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Garlic Water Recipe #1 (Deterrent and Pesticide)

4 cloves of garlic,
1 tablespoon oil (mineral is preferred),
liquid detergent (as in dish detergent),
and water.

This recipe is looking to make a product that will not only deter small aphids and spider mites, but also kill them. The dish detergent in the list of ingredients is that determining factor.

     1. You will need to slightly crush 4 cloves of garlic. It’ doesn’t need to be fine, just enough to break the outer layer allowing for the next steps.

     2. Add this to a jar with 1 tablespoon of mineral oil. The garlic needs to be crushed enough to allow the oil to have maximum contact. If you want to mince it, you can, but I found just crushing the garlic had the same effect. Let this sit for 1-2 days, allowing enough time to the sulfur to leach into the oil.

     3. Once the solution has had time to extract all it’s going to, then strain the garlic pieces out, leaving just the oil.

     4. Add 1 teaspoon to 1 tablespoon of dish soap, depending on how bad your infestation is. If you are using this just as a preventive measure, go with the teaspoon. Just don’t use too much.

     5. Add a pint of water (half a liter) to the oil and put this in a spray bottle. If the leaves on your orchid start to yellow the next day, dilute this amount by half.

Each orchid will be sensitive to the solution, and there is no one formula fits all. You’ll have to adjust this to your needs and dilute or make it more concentrated as your orchid handles it.
So that is how you add garlic water to your orchid mix. I suggest using it only as pesticide and fungicide, instead of a regular fertilizer supplement. Even though there isn’t harm in doing so, adding garlic in a higher concentration could bring severe setbacks to your orchid growth.

In all, I hope this helped. Happy Cultivating!
Signature Amanda Matthews
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This article was published on:
September 7, 2021
Written by:
Amanda Matthews
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