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Top 3 Things Mold Needs to Grow

by Joslyn
green molds

What Does Mold Need to Grow?


According to Michael Pugliese, author of The Homeowner’s Guide to Mold, there are three main necessities that mold spores need to grow and thrive:

  • Moisture

Mold spores need moist or damp areas to grow and reproduce. Watch for flooding, leaky pipes or windows, etc. Also excess moisture in the bathrooms, kitchens, and laundry rooms are prime areas for mold growth.

  • Food

Mold spores need food – in the literal sense as well as other materials (i.e. cotton, leather, wood, paper products and others). The most dangerous materials mold loves to grow on, are porous materials (beds, couches etc). It’s often impossible to remove mold growth from these items.

  • Optimum Temperatures

Mold spores thrive in temperatures 32 and 120 degrees Fahrenheit. Temperatures from about 70 – 90 degrees are the most conducive for mold growth. Chances of mold growth are heightened greatly between those temperatures. You may be wondering why mold can grow in your freezer. Mold doesn’t die when temperatures drop below 32 degrees, they lay dormant until temperatures raise, or they are set out to warm up.

Favorable Conditions for Mold

Michael Pugliese, author of the same book previously mentioned, also offers 5 tips describing favorable or unfavorable conditions for mold growth:

  • A relative Humidity of roughly 50% or higher

A good preventative measure would be to purchase a hygrometer to measure humidity levels in your home.

  • Damp or Dusty Conditions

Avoid developing piles of rags, clothing or other mold food sources.

  • Stagnant air

This explains why overly “tight” homes designed for energy efficiency can have mold problems.

Unfavorable Conditions for Mold

  • Ventilation

Good circulation throughout the home is important to eliminate dampness or potential moisture; especially in attics, basements, crawlspaces, laundry rooms.

  • Dry Air Indoors

Make sure to keep your home’s relative humidity down below 50%.

Further Recommended Reading:

Joslyn from the MoldBlogger Team

Source: Pugliese, Michael. “The Homeowner’s Guide to Mold.” 4-5.

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Mike August 27, 2009 - 12:49 pm

Though I’ve never had freezer mold problems in my kitchen fridge/freezer, I’ ve been thinking about getting a small non frost free/manual defrost chest freezer, and wonder if I should be concerned about storing anything in there for a long time. If I defrost it yearly and dry it and run it for a few days before restocking it, could there still be a chance of eventual mold growth?

Holly Scott September 3, 2009 - 5:45 pm

we are reaserching mould at school. and we need to know what mould needs for growth. thankyou for creatin this website. It is VERY helpful

Gordon Callison November 26, 2009 - 4:34 am

Within five minutes of my blog on an ear mold infection, a reader, who wrote me and e-mail. Said he was Dr. James Trogun from Toronto, Canada’s Doctor’s Clinic. Suggested i refrain and completely ELIMINATE these problematic trouble makers: SUGAR, YEAR AND WHEAT.

Thanks you all
ps If my e mail isn’t publicized, I know who read my blog and came aboard to help me. I will do it. Gordy at:
art by gordy.com

malcolm February 22, 2010 - 12:17 pm

i nead help mold is growing in my finger nails and betwen my toes email me fo advice to get rid of it

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Theresa Myrick June 29, 2010 - 8:13 am

I am told that mold cannot grow on cement floor if carpets are installed over it. Is this true??

valerie Crossley December 10, 2010 - 5:12 pm

we have what we thought is Mold in a bedroom cupboard

we had it tested and it has high signs of yeast
I have had coughs on and off for a year and a half now Very bad coughs and they have been treated by antibiotics

but the antibiotics clear it up then it is back again
I get nauseaus and very tired recently
I have now gone to a Pulmonary specialist He asked lots of questions and also asked re acid which I do have but it does not really upset me, they did allergy tests also
I gave the specialist the yeast results which was done in our home and asked could it be causing a problem for me he really just put it to one side and said he did not know how it could cause a problem but that is not what I understand re reading about Mold on the internet
One of the allergy tests was for Aspergillius and it came up as not a problem
so could the mold in my cupboard be causing a problem we have taken all my clothes out of the cupboard and washed them and sealed the cupboard with tape until we get it cleaned
It is a rented home and the cupboard is beside the shower. If we get special cleaning stuff can we or the owner clean it or could the mold be in the wall which is an outside wall and would that mean the back wall which is an outside wall in the cupboard have to be chipped out
Please let me know re Mold and my health and also does our wall have to be dug into or knocked down. my husband if it is a mold problem has no bad symptoms other than fatigue we are both in our 60’s
any help appreciatted

with thanks

bay eberly February 11, 2011 - 12:45 pm

it helped a bunch with my science fair project.

a September 7, 2011 - 2:09 pm

antibiotics are made from molds.

Abbi January 24, 2012 - 5:16 pm

This helped my science project on mold alot!!!!!

Helen Wimmer February 4, 2014 - 5:54 pm

I have believed for 2 yrs that I have a parasite infection. Four dr shave told me I am in need of a psychiatrist. Could it be related to a mold infection? My entire ears have a black look to them, they are swollen with lumps. .Coming out of the ear canal is black and feels crunchy. When I use the hairdryer my body turns black colored. I am Caucasian with blue eyes. I used to have blond hair but am forced to shave my head. I have hyperhydrosis, I am always moist somewhere. I wear dentures after having 15 teeth pulled. I am hypothyroid a. I use hormone replacement, I am 59 and had a total hysterectomy 15 yrs ago.

Shooting Ranges UK September 20, 2014 - 10:54 am

At last a site that spells it out clearly. Thanks for the article

Felona October 10, 2014 - 8:38 am


Ashley Smith March 19, 2015 - 5:44 pm

Helped me so much on Homework

Mokgadi April 12, 2015 - 8:54 am

This website is very helpful i wouldn’ve known where to start without it..thanks it amazingly great.

Bo December 12, 2015 - 10:37 am

I have a friend and a sister who have lived for decades in Miami Beach using little a/c, even in summer, and all this time have seen no mold in their condos. They have had thousands of hours in their condos when humidity was in the 70%s and sometimes in the 80%s. So what gives. I won’t close my windows in winter in South Florida and run the a/c to get humidity into the 50s. Ridiculous. That would require temperature to be brought down by a/c in the mid 60s. I feel perfectly comfortable in upper 70s.

wendy January 15, 2016 - 6:03 pm

I closed my camper for 6 months. When I opened it back up everything (couches and bedding, clothing) had green mold on it I cleaned it all but the smell isn’t going away. What should I do?

Helene Gaul April 21, 2016 - 9:01 pm

I live on the south coast of NSW Australia about 500 metres from the beach. I have a problem with mould in one downstairs room in my house. A timber coffee table and a leather couch are regularly covered with mould. I have a large sliding door into the room and it is open 10 hours a day. When the mould appears I clean with bleach then clove oil to prevent return – that doesnt work.

I have removed the coffee table and will soon get rid of the leather couch. Is there any furniture material that doe snot grow mould?

nicholaststanaton November 7, 2016 - 9:52 am

what if you lived in a hose of all mold

;D November 15, 2016 - 1:40 pm

Science fair project on rotting food…. this helped bunches!!!!! THX

hally jackson November 15, 2016 - 1:46 pm

I didn’t know these a lot of these things!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! THX FOR THE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Charlett December 8, 2016 - 10:22 pm

Vinegar is the only stuff that kills mold. Bleach just makes it white so you can’t see it and I’m sure it makes is clean mold lol. But vinegar destroys it. Mold gets into your lungs and grows in your sinus. Mold is fungus and cancer is fungus. Everyone should eat vegetairian diet no sugar very little lamb and because of animal diseases no chicken or beef. No sugar. Roundup and fluoride is in all the canned food and vegetables at the supermarket. Roundup is glyphospate and if you have too much it will make you put on weight and you won’t be able to lose weight no matter what you do. Parasites, fungus and roundup and fluoride.

These are the reasons why we are sick. Other diseases have to be looked at individually.

worriedaboutinlaws January 2, 2017 - 8:00 am

My inlaws have a fridge in their basement. Everything that comes out of that fridge has a different taste to it. By opening the fridge, it appears clean. But this scent can even make a carton of cream or eggs taste bad. It’s been several years and neither of them taste it. But anyone who doesn’t live in their house can. Is it possible for mold to grow behind refrigerator walls? Could that mold be so potent that it could give the food a distinct ‘flavor’? If that is what the problem is, could their be health concerns associated? Because they’re not directly ingesting whatever it is, but at the same time their food tastes like whatever is causing the problem.

Binky Boo February 11, 2017 - 9:27 pm

I have been suffering from mold exposure for quite some time now. It is at my place of employment and, as a result, at my home. It’s in my hair and is active all day long. It is at the point now where at night when I turn the lights off to sleep, fuzz, lots of fuzz, grows out of my arm. Covers my arm completely. My skin under the fuzz turns black. I have “stuff” oozing out of my pores. Mainly my tear ducts. My skin changes completely. Sometimes it looks like the after effect of being in a fire, sometimes big sections sink in where I can sit a tennis ball in the dip. This is just the tip of the iceberg! If I was to tell you everything I’ve been experiencing, you would think I’m a nut case! I have tried everything and I mean everything. I even sprayed myself with bug spray one day just to get 5 minutes of comfort. I’m reaching out for suggestions, other than the popular vinegar, baking soda, essential oils, etc. I’ve tried them. Nothing works. Please, any help is greatly appreciated. Also, in a very dim light, I see black spider like things that wiggle fast. There’s hundreds of them and they just go in swarms covering everything. There is so many and they wiggle so fast it looks as if they get tangled up with each other. They are not visible in the light. In the daytime hours I can feel them but can’t see them. I can’t find anything that explains what these are. I’m wondering if this is what mold looks like before it turns fuzzy? Please help.

Dorothy King March 1, 2017 - 7:33 pm

I just now bought a new Bunn coffee maker. I love it. but since it holds hot water in a resavor in back of it my daughter is afraid of it holding mold. The water stays at 200 degrees all the time.

nero April 1, 2017 - 6:16 pm

Thank you for the article. Things inside freezer sometimes, very very gradually, can get mold – I was surprised to find it inside packaged food. Probably a prior contamination.

Speaking about humidity, personally, for example, humidity below 50% is a pain – my skin, hair, and most importantly mucous membranes become dried out. Like being trapped in dry sand. So, imo, if it is a bedroom, don’t dry yourself out. We need humidity too. Dry mucous membranes are a gateway to bacteria and fungi. Nobody wants mold growing in their body.

Blake & Oliver August 8, 2017 - 10:32 pm

Very useful for studying at school, thanks!

Susan September 18, 2017 - 8:40 pm

Binky Boo , I was wondering if you found a solution to your problem . I’m going through the exact same thing. I’m about to loose my mind. I also thought it was a parasite but now think it is mold. I have the same ezct symptoms you do. Could you please send me anything that could help me . Please would ever be so grateful.

audrey February 9, 2018 - 9:28 pm

has anyone looked into the use of salts? like meditranean sea salt? it has so it says 90 minerals and elements in it. i think 15 of those elements are not supposed to be ingested at any miniscule amounts which would be a good reason why a lot of people find a spot in their lung and then bam have full blown brain cancer and in a few weeks dead???? something as simple as that so called pure salt has radioactive elements in it. I almost wonder why black mold is not considered an element? it’s just as bad. does anyone think Salt could be a contributor to mold growth. salt is one of those things that stays behind and gets in the cracks of things and dosn’t evaporate away, not to mention the water that it can produce in the body and linking to human and mushroom alike breathing in oxygen and out co2 edema in our body retaining water and mushrooms love salty atmospheres. is their a way to take salt out of the air or wood and would that kill spores if we had a way to destroy the salt in specific items like already saturated wood. I think bleach is also considered some kind of salt. so it wouldn’t kill mold completely either. maybe it would make it come back from spreading spores with a wash cloth. i mean billions of spores would be covered in a square inch of surface area and could easily amass anything that it touches might grow more mold just using the rinse water. so using gloves would be a must to try to conquer black mold and lots of paper towels steam cleaner using near boiling water. i don’t even think that works so well. I’ll tell ya what tho ear yeast is no joke I’ve seen people go clinically insane thinking bugs are in their ears and they think whoa buddy crazy stuff even doctors tell them their nuts aint nothin their. and all it is is a case of Yeast in the ears. it’s black and sometimes pussy spews from them gross but very factly. mold will make you nuts. black spots that itch on your skin and people tell you theirs nothing their. if you can feel it hit your face when you open a cupboard and a mass web of nothing hits your face makes you itch like bugs its a molded environments. I believe a lot of what I say here. and people going nuts over mold is no laughing matter. mold will make a person crazy and it’s a major health issue cauze is in the mold.

Jackie Clover March 27, 2018 - 9:16 am

I have a recliner that I bought brand new, I noticed a musty smell a couple of month after I got it. I decided to shampoo it. Than my troubles started. Every time I sit on it I itch. There is something on my clothes. If I go get ready for bed, I itch until I wash everything on the bed. My husband thinks I’m losing my mine about this, but I want to get rid of this chair. I have sprayed it with bug killer. I’ve never seen anything on it. I have shampooed it a lot. I won’t sit on it anymore and I’m ok. But if I say it’s OK it’s on again. What do I do? HELP


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