Top 3 Things Mold Needs to Grow

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). Its 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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22 thoughts on “Top 3 Things Mold Needs to Grow

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  4. 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?

  5. 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

  6. 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:
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  9. I am told that mold cannot grow on cement floor if carpets are installed over it. Is this true??

  10. 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

  11. 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.

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

  13. 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.

  14. 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?

  15. 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?

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