White Mold

How to Identify and Control White Mold

White Mold

Here are tips on how to identify, control, and prevent the fungal plant disease white mold.

What Is White Mold?

White mold, also known as sclerotinia, is a fungal disease that affects over 360 different plants, including beans, peas, lettuce, and members of the cabbage family. White mold is sometimes called timber rot when it affects tomatoes. Mold symptoms appear on blossoms, stems, leaves, and pods that have water-soaked spots. Leaves will wilt, yellow, and die; pods may rot.

Host crops are most susceptible during flowering, but young seedlings are also very vulnerable. White mold typically infects the plants early in the spring or summer and then develops unnoticed for a while. White mold fungus releases spores when the weather is cool, and these spores can be carried by the wind and infect other plants. This is why it is so important to catch white mold and destroy infected plants quickly.


    How to Identify White Mold Damage

    White mold symptoms vary depending on the environment and type of plant, but here are some common ones:

    • The stem might first appear to have a water-soaked part. At this point in the infection, the plant will look healthy from above.
    • Wilting of individual stems, especially at the base with tan discoloration.
    • Infected stems may appear to have tan to dark brown lesions on them. From these lesions, a dense, cotton-like growth will form under conditions of high humidity.


    Photo Credit: The Ohio State University. White mold takes over a bean plant with its dense cotton-like growth.

    Control and Prevention

    How to Control White Mold

    • As soon as you notice any diseased plants, destroy them immediately.
    • If your soil is infected, remove as much of it as you can and replace it with clean soil.
    • You can use a barrier, such as plastic or mulch, to cover the infected ground to prevent the spread of the disease.

    Prevent White Mold

    • Be sure to use well-drained soil and space your plants properly to avoid crowding. Also, remember to avoid areas with poor air circulation.
    • When watering your plants, try not to water the tops of them. Or water the plants early in the day so they have the chance to dry before nightfall.
    • You can also spray your plants with an approved fungicide to help prevent infection. Spray the plants right before they bud, then spray again a week later.
    • Control your weeds. Weeds can host this disease and spread it to your plants.
    • If possible, remove all crop residue after harvesting. If residue is left, this disease may develop in it. White mold spores are long-lasting, so they will survive the winter if given the chance.


    Reader Comments

    Leave a Comment

    White mold

    What do I do when this happens to my house plants?
    I put them outside, weather permitting, in spring and bring them back in when the weather begins to get cooler. (Fall)
    Thank you, Mary Formichelli

    nice post

    Thanks For sharing this information. It’s Nice..!!!

    great post

    This is a great post. I like this topic.

    White mold

    Hi, is it safe to eat the veggies in garden with white mold? If not, should I get rid of the dirt and start over? What do I do?? Thx

    safe to eat white mold veggies?

    The Editors's picture

    No, it’s not recommended. See here, and read above:

    • As soon as you notice any diseased plants, destroy them immediately.
    • If your soil is infected, remove as much of it as you can and replace it with clean soil.
    • You can use a barrier, such as plastic or mulch, to cover the infected ground to prevent the spread of the disease.

    White fungus

    There is a white fungus growing on the soil in our raised vegetable garden. We used chicken manure as fertilizer in the spring. The plants are growing great, but is it safe to eat the vegetables?

    white mold

    I planted my first 8 x 2 raised garden. I put boards on each corner, with wire fence all around, nice. I put tomato's on one end & squash,
    bell peppers & cucumber on the other. I covered the entire garden with sheets for more than a week, to prevent severe thunderstorms from destroying my plants. I took the sheets off today to find white mold under the first two tomoto plants, on the soil only & not on the plants. I scooped out all the mold from the soil. I was so excited to have vegetables starting to grow on all plants. Am I screwed after all my work, cost & excitement or can my garden be salvaged from this mold. Please please advise me what to do?? Thank you.

    White Mold

    The Editors's picture

    As long as the garden receives proper air circulation and is allowed to dry out between waterings, the white mold should be kept at bay. Consider placing landscaping fabric over the soil around the plants to prevent mold (and other diseases) from splashing up onto the plants from rain.

    White Mold or White Fungus

    I have white sections outside in raised bed that is not yet even planted. Paid a good price for that dirt and don't know why it is showing up.
    Also have one bed planted with lettuce and beets that has a greenish coating over top of dirt. What's going wrong? Please help me.


    i got a like a cotton white fugus on my roses what do i need to get rid of it

    Powdery Mildew on Roses

    The Editors's picture

    It sounds like your roses may have powdery mildew. If possible, remove the infected leaves and treat the rest of the plant with a fungicide, which you can find in your local hardware store, garden center, or online. Powdery mildew forms when conditions are warm and humid, so if you happen to be watering your roses from overhead, try watering at the base of the plant instead to reduce moisture around the leaves.

    Moldy plant food

    I purchased a Sour Sop tree about 2 months ago, shortly after buying the tree the leaves started to get brown spots. I removed the leaves and it looked like the tree was doing ok now some leaves are spotting again. I did not have food for it so I used raised bed food for vegetables which ended up molding. I replaced the food with citrus tree food as well as a thin layer of cedar chips to keep the bugs off and again it molded. I did have a raised bed garden and was using compost tea to water the plants. Out of about 30 plants I have 3 left. The soil did mold is that because of the compost tea? I also have a mite problem which may have aided in the plants dying, I had them inside a lot of the winter which is where the mites are.

    Sour sop problems

    The Editors's picture

    Have you contacted the source from which you purchased the plant? It may have been diseased or at least your vendor may have been able to provide some guidance. These are tropical plants that are vulnerable to a number of pests. That said, it is not a plant with which we have any experience, and would advise you to read up on it here: https://hort.purdue.edu/newcrop/morton/soursop.html (Perdue is an excellent resource). We would also suggest that you contact the cooperative extension nearest you (chick on your state here: http://www.almanac.com/content/cooperative-extension-services ) If the folks at the extension do not have an answer they may very well refer you to a colleague at a service that is knowledgeable.

    "White Mold Mildew"

    Barnstable Co. Ext. Serv. gave me a bad diagnosis, since your article does not seem to correspond to my situation. The "white mold" I have is NOT on the plants, but on the soil surface. There is nothing growing on plants, but I was worried about it's effect on my plants. It is ONLY on clear soil. It fades to gray color and disappears, but returns with moisture. It's spotty, in many areas, but only on clear soil. It's like fuzzy white ground cover.
    Can you give me some better advice?

    White Mold on Soil Surface

    The Editors's picture

    If you are talking about potted plants, it could be a harmless (and common) fungus called saprophytic fungus. It usually results from a combination of over watering, poor drainage, and old or contaminated potting soil. If any or all of those conditions ring true, repot the plant with new soil (and possibly a pot that drains better) and water less frequently.


    My moon flowers started

    My moon flowers started wilting and the leaves curled one section at a time, I checked around the roots and see white substance just below the soil surface . Now the entire plant has wilted, this is a well established plant I've had for 3 yrs. what could this be?

    Wilting Moon Flowers

    The Editors's picture

    Hi Shirley,

    There are a number of plant species with the common name of moon flower, but I am going to guess you have a Datura plant, in which case you may be looking at any one of the following viruses: Datura wilt virus, Datura distortion mosaic virus, Datura rugose leaf curl virus, or Datura quercina virus–all exhibit the wilting symptom. It is important to know if it is a virus and which one it is before treating it. I suggest taking some tissue cuttings (leaves and stem) and sending the sample to your local Cooperative Extension Office for testing. They will tell you a course of action to take.

    White Mold

    I have what looks like it could be white mold on the branch of a 4 foot tree that I received from the National Arbor Day site. It's just at the top of the tree, about an inch or two long area on a branch. Can it be washed off or is there a way I can get rid of it without killing the tree? The leaves have started to wilt, so I need to do something quickly. I live in Missouri, so humidity is high and there's not much we can do about that...

    Powdery Mildew

    The Editors's picture

    It’s hard to say for sure, but what you describe sounds like powdery mildew fungus, which won’t kill the tree, but can be unsightly and might compromise the tree’s long-term health, if allowed to spread. Go ahead and remove that branch, then monitor to see if the spores are spreading. There are a number of non-toxic products on the market for treating it, and even a few home remedies!

    It's spring time planting in

    It's spring time planting in Michigan once again and tilling a second time before planting vegetables. Many gardeners had mold issues last year including me. What can I put in the soil as I till as a preventive to mold? Baking soda?

    If you notice mold turn the

    The Editors's picture

    If you notice mold turn the soil over and bury the mold. Keep the soil as dry as possible and only water the individual plants not the entire garden. It also helps to add new fresh soil to the garden if the mold issue doesn't go away.

    If I have what looks like

    If I have what looks like white mold only on the soil, not the plants, can I just remove effected soil and apply a ground cover? Do I have to remove the soil? Can I just apply wood shavings? It appeared after we added chicken manure mixture to our garden. Is it related?

    Hi, Jennifer: Just to be on

    The Editors's picture

    Hi, Jennifer: Just to be on the safe side, sure, go ahead and remove the affected soil, then proceed as usual. Mold is everywhere, though, and usually doesn't pose a problem in soil, as it will dissipate once its growing conditions (organic food, a lot of moisture) deteriorate. Mold on plants is another matter, as you recognize, as is nonwhite mold. Thanks for asking!

    I have some indoor potted

    I have some indoor potted plants. Some had begun to get "rootbound" being out of new soil I baked a lot of it to sterilize it. It was too late for the transplant for most and they died anyways. When removing from their pots for discard, I noticed white mold growing specifically where the inside of the pot meets the soil. I have one that survived and its pot has the mold in the same manner as well. So I watered around the edges with a peroxide solution. What else should I do? Can this kill my plant? Should I simply repeat the peroxide treatment and keep the problem at bay until I can harvest and discard the soil? This plant is 3-4 weeks from being ready to harvest

    Hi Branden, We suggest that

    The Editors's picture

    Hi Branden,
    We suggest that you remove the plant from the pot. Discard any soil that has mold on it and replant in a new bigger pot with light potting soil for containers.

    can you eat the veggies after

    can you eat the veggies after you remove the mold from the plants ?

    Hi, P.J.: Excellent question!

    The Editors's picture

    Hi, P.J.: Excellent question! From a technical standpoint, the answer is yes. Assuming that you mean a leafy veggie, and not something that you would peel or de-pod anyway, it is indeed possible to wash them thoroughly enough to eat (say, with a very weak bleach solution, then assiduous rinsings), especially since some might end up being boiled anyway. From a practical and 100% safety standpoint, though, we wouldn't do it.

    I can see there are white

    I can see there are white powdery spots on some of the leaves of my yellow
    zucchini. Do I have to remove and destroy the plant or will spraying these leaves with a fungicide help save the spread?

    Hi, Lea: Meet powdery mildew.

    The Editors's picture

    Hi, Lea: Meet powdery mildew. Before doing anything drastic, just try washing it off with a water spray. (Some folks say plus milk, and/or plus baking soda, etc.; we say keep it simple, at least to start.) Do it in the morning so that the leaves have time to dry out before the humid part of the day, humidity being the main culprit, not water itself.

    hello, your site and info has

    hello, your site and info has been super helpful to me. I am growing quite a few things from seed right now inside and everything seems to be going great, only problem is white mold in some soil and on the containers I'm growing them in. Its not on the actual sprouts though. Any idea what I can do or if I leave it will it ruin all my plants? I'm growing veggies, fruit and herbs. Like I said though, they seem to be growing like crazy.



    Sign up for our email newsletter by entering your email address.

    BONUS: You’ll also receive our free Beginner Gardening Guide!

    The Almanac Webcam

    Chosen for You from The Old Farmer's Store

    Sign up for our email newsletter by entering your email address.

    BONUS: You’ll also receive our Almanac Companion newsletter!