Is Diatomaceous Earth Good for Houseplants?

You have houseplants, you’re looking to keep them healthy, remove unpleasant odours or bugs, and hoping they will continue to grow well, but you’re wondering what material is good to use and if Diatomaceous earth is the best choice.

Diatomaceous earth is good for houseplants; however, it is much more effective when combined with potting soil. Diatomaceous earth improves drainage, increases the air the root zone receives, and helps loosen the usually compacted potting soil.

Diatomaceous earth has a lot of uses including helping houseplants. Keep reading to learn about the uses of diatomaceous earth, its benefits, and its drawbacks.

What is Diatomaceous Earth?

Diatomaceous Earth is a natural powder, it is the fossilised remains of small organisms such as diatoms. Also known as kieselguhr or diatomite, Diatomaceous Earth is used to kill and scare away indoor pests, for example, mites’ ants, and maggots, to de-odorise plants and to improve plant drainage.

80-90% of Diatomaceous earth is made of Salt and its porous qualities make it easy to use. It mimics the density of baking powder therefore is easy to sift and spread and add to plants.

Diatomaceous Earth can be harmful to humans if it gets into the lungs, however, by taking the correct precautions it is perfectly safe to use. 

Will Diatomaceous Earth Kill Houseplants?

Diatomaceous earth will not kill any types of houseplants. It is a natural product that can be added to the soil without any concerns.

Even using too much Diatomaceous earth will not harm plants and it can be removed if needed. Due to its white complexion, it is easy to identify and as such remove without damaging the plant. It can even be sifted out of the dirt, should stubborn bits of material not be easy to remove.

What Can Diatomaceous Earth do for Houseplants?

Diatomaceous earth does not kill houseplants, it does the opposite there are many functions of Diatomaceous earth. 

  • Diatomaceous earth is an insecticide-This means that the earth dehydrates pests, killing them in a few days and protecting plants. In addition, diatomaceous kill larva before they can emerge from the soil.
  • Diatomaceous earth improves the drainage-This type of earth can hold water up to four times its own weight, in addition, it can retain nutrients. Its ability to hold high amounts of water means it is especially useful for plants such as cactus or bonsai. 
  • Diatomaceous earth can deter mould– Diatomaceous Earth has dehydrating properties, which means it can help to reduce white surface mould and soil moisture. This can also deter pests such as fungus gnats.
  • Diatomaceous earth can be used as a deodorizer– Sometimes plants can begin to smell, for the most part, this is a natural occurrence, but it can occur due to overwatering. Adding diatomaceous earth can remove unpleasant smells from plants.
  • Diatomaceous earth also releases moisture into the plants slowly and as a result, it reduces the number of times soil needs watering.


How to use diatomaceous earth?

Diatomaceous earth isn’t difficult to use however there are a few ways to ensure its effectiveness and the users safety.

  • Firstly, apply a mask and goggles to protect yourself from the power. Keep children and pets away from the plants until the dust settles.
  • Move plants away from windows or windy areas to ensure the powder doesn’t blow away.
  • Use diatomaceous earth first thing in the morning-preferably after the dew has settled or after light rain. It is worth checking the weather forecast for outside plants as heavy rain can wash away diatomaceous earth.
  • A good mixture to use is 2 cups of diatomaceous earth to every one gallon of water. Make sure to calculate the correct amount of material to use for each plant, as to not over or under water-which could potentially harm the plant.
  • Use a dust spreader or spray to put the powder onto the soil. Make sure to cover the entire plant including inside and outside of the leaves as insects can avoid the material if gaps are left.
  • Leave the material to dry, the dust should stick and then become effective.

Using diatomaceous earth is fairly simple however there are a few precautions to take to ensure the safety and efficiency of the material.

How Long Does it Take for Diatomaceous Earth to Work?

Diatomaceous earth works almost immediately. They dehydrate bugs and beginning killing them straight away when making contact with the soil. However, it can take a few days for all the bugs to die.

However, when water touches diatomaceous earth it can be washed away, since diatomaceous earth is a very fine powder. Therefore, it is worth going through some trial and error to work out the best time to use the material and if it should be used with or without water.

In addition, different bugs take different amounts of time to die. For bugs such as ants, it can take less than 24 hours, however beetles and gnats can take up to 21. So, take this into account, and don’t worry if bugs don’t immediately die.

Diatomaceous earth should start working immediately but some bugs may take a few weeks to die. If it doesn’t work within this time frame more can be added. In addition, if water is added straight after, it may limit the effectiveness of the material. Aim to add diatomaceous earth to dry soil.

How Often Should Diatomaceous Earth be Used?

Diatomaceous earth should be used once a week. Once added to the topsoil it should be left for 7 days. If the given problem is solved after 7 days, it doesn’t need to keep being used. However, if the problem prevails, continue to use it every week. For extreme infestations, it’s worth using diatomaceous earth for at least a month.

Many also suggest reapplying diatomaceous earth every time it rains, this is as the powder can be washed away by the rain. 

Of course, this is not necessary for indoor plants but lining up watering plants with using diatomaceous social could be effective for the plant’s health.

Therefore, diatomaceous earth can be used every 7 days but it’s worth considering individual needs when setting a usage schedule.

Are There any Negatives of Diatomaceous Earth?

It is reasonable to question the downsides of materials used in the home, especially regarding safety, health, or environmental concerns.

  • Diatomaceous earth is a fine powder and can get into the lungs and cause irritation, therefore it is a good idea to wear a mask. For those who are asthmatic or have other lung conditions, it is worth avoiding using diatomaceous earth.
  • Diatomaceous earth needs to be kept dry to stay effective. Therefore, it may be tricky to store, especially for those in humid environments. In addition, it may be less effective on certain types of plants for example ferns.

Therefore, there are some negatives to diatomaceous earth such as health risks. These health risks can be reduced with the correct precautions. In addition to this, any issues with the capabilities of the product can be avoided by making sure the material is used appropriately and correctly.

So, is Diatomaceous Earth Good for Houseplants?

When used with other materials diatomaceous earth can be good for houseplants. They can be used as an insecticide, to improve drainage, and to deter mould.

However, they do have some downsides. For example, the potential health risks and aversion to water. These downsides can be mitigated and avoided therefore diatomaceous earth can be useful for houseplants, boasting a multitude of benefits including keeping the house fresh smelling, and insect free, especially those with high amounts of water such as cacti and bonsai.

Kate Inskeep

Kate Inskeep is a mom of three from Illinois who loves growing things. She fell in love with houseplants after a friend gifted her some succulents. Before long, her windowsills were full of plants, and she was hooked.

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