top of page
  • Writer's pictureStephanie Lum

Can Your Houseplants Make You Sick?

Updated: May 25, 2023

We all know that many houseplants are toxic, and you shouldn't be chewing on your philodendron, but I bet you don't think too much about the soil those plants are in.

That soil can harbor dangerous little spores that can spray into the air.

If you are allergic, these spores cause you to feel awful - irritable, brain foggy, tired, anxious, and can give you chronic sinus congestion and headaches.

So let's find out why the soil your plants live in matters (a lot) and what you can do to coexist.

Potted green houseplant with Dr. Brian Lum logo

Soil-Based Allergens

Many people assume that green plants (those with no flowers and no pollen) will automatically be allergy-safe indoor plants.

If your indoor environment doesn't get a lot of sunlight and is humid, these are perfect conditions for mold to grow.

You may even pull off a few mushrooms off the topsoil of your houseplants.

While these mushrooms are a sign of healthy soil and are (usually) not hurting your plants, they can be toxic if ingested by kids or pets and can give off spores which you can react to.

A lot of plants can also raise the humidity levels of your home to the point that it causes black mold to grow in places like your kitchen and bathroom.

Allergies Can Cause Severe Symptoms

Most people think of a runny nose and congestion when they think of allergies. Environmental allergies like mold can actually cause a wide range of symptoms like

  • Stomach Cramps

  • Brain Fog

  • Diarrhea

  • Constipation

  • Fatigue

  • Dizzyness

  • Migraines

  • Headaches

  • Tinnitus

  • Ear Congestion

If at any point your symptoms become severe or impair your breathing, see your doctor immediately.

What To Do

1. See If Your Houseplants Are To Blame

Examine the soil - see anything? Take off anything that is not supposed to be there, like mushrooms, or yellow or white powdery mildew.

Ensure that you have potting soil in your pots - not regular soil, this will ensure good drainage.

Examine the pots for signs of mold growth.

If you are sensitive to allergens, indoor terra cotta pots may not be the best choice for you because they pull moisture away from the soil and mold frequently grows on the outside of the pot.

2. Quarantine

Clean the leaves with a damp sponge to ensure your not reacting to something else (like dust) and put them outside on a porch.

Sunlight is a great way to help dry out and kill mold spores in soil.

If it's too cold out, put them all in one room and keep the door closed.

Be sure to vacuum and clean surfaces once the plants are removed.

Feel better? It may be your houseplants!

Scroll down to find out some tips to reduce allergens in your potting soil.

3. Don't Rule Out Other Causes

Remember that even if you found mushrooms or mold on your soil it may not be the culprit.

A damp environment may have caused mold growth somewhere else (like your bathroom) and you may be reacting to that.

4. Testing

Testing yourself for mold or other environmental toxins is easier than you think.

Functional medicine testing can determine the cause of your allergy symptoms.

A consultation with a functional medicine practitioner can help get your body back to filtering environmental allergens naturally.

Read more about Specialized Testing.

How To Prevent Mold Growth On Houseplants

1. Not Too Humid

A 40-50% indoor humidity level is considered ideal.

That humidity level may need to be higher or lower depending on the season.

If water is condensing on your windows or you start seeing mold growth around windows or in your bathroom - its too high.

2. Get Good Soil

Get good quality, sterile potting soil with good drainage capabilities.

Often spores come from fungus growth from contaminated soil, don't reuse soil.

3. Get The Right Kind Of Pot

The wrong size of pot or the wrong material can prevent adequate evaporation from the soil.

Indoor, moist, dark environments may not be the best place for terra cotta as this material pulls moisture away from the soil onto the outside of the pot.

Mold growth can occur easily on the outside of these pots.

A local plant nursery will be able to tell you the right size and material for your plants as well as some tips to reduce mold growth in soil.

If you are reacting to your plant soil, repot your plants.

Clean the pots, rinse the roots and repot the plant with fresh, sterile soil.

4. Sunlight

Sunlight is an effective killer of mold spores in soil. Give your plants a sun bath!

If your plant is sun-sensitive, you can use this method to kill mold spores by spreading the soil itself in direct sunlight.

5. Don't Overwater

Be sure to follow care instructions when watering your plants.

Soggy soil isn't just bad for mold growth, its not great for your plant either.

Empty drainage trays at the bottom of your plant about 15 minutes after watering.

Don't let your plant sit in water!

6. Use A Natural Mold Inhibitor

May plant parents swear by sprinkling some cinnamon or apple cider vinegar to the topsoil of their pots to inhibit mold growth.

Just a spoonful per plant is a good amount - a little goes a long way!


Reviewed by Dr. Brian Lum

If you think that you may have a medical emergency, call your doctor or 911 immediately.  No action or inaction should be taken based solely on the contents of this information. Nor should you ever delay seeking medical advice or treatment due to the information contained on this Website.


Commenting has been turned off.
bottom of page