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Slimy Fungus on gravel



  • Birdy13Birdy13 Posts: 595

    Re this horrible slime problem, I've noticed that some people have tried sodium carbonate (also known as washing soda, soda ash or soda crystals) while others have tried sodium bicarbonate (baking soda and also an ingredient in baking powder and more commonly sold in powder form).

    The two chemicals are similar but not interchangeable as they have different chemical formulas (sodium carbonate is Na2Ca3 while sodium bicarbonate is NaHCO3).

    NB The bicarbonate used to be used as an anti-acid indigestion remedy (before a greater variety of tablets were designed for this job) whereas the carbonate form definitely can not be used in this way.

    Although I am not a chemist I do know that each will react differently in each given circumstance. This should be considered before buying up a load of either chemical in case you get lumbered with the wrong one for your slime problem.

    I would imagine the best way to tell which chemical suits your slime problem would be to do a test in 3 sets of flower pots - one set with sodium carbonate, a 2nd set with sodium bicarbonate and a 3rd set with neither - used as a control.

    Keep them all separate, ie not touching, but in the same area as each other to create a 'fair test'. Each set should eventually give different results to enable you to see which chemical is most effective.

  • An update to Slimy Fungus / Nostoc Commune.

    Dissolve 1kg bag of Dry Pak Fine Soda Crystals( Sodium Carbonate ) in hot water in a 10ltr 

    watering can then fill with cold water. For an area 20' X 12' I used 3 cans. Repeat 2 weeks later.

    Cheap - Easy - Safe and I'm still compleatly clear nearly 2 years later. 

  • Bee witchedBee witched Scottish BordersPosts: 730

    Hi Margaret,

    Thanks for the update ..... I get this most years so will try your method.



    Bees must gather nectar from two million flowers to make one pound of honey   
  • Hi Margaret,

    Having spent the morning scraping and sweeping up this stuff from my patio on the east coast of Ireland , I look forward to spraying it with soda crystals tomorrow. We have had it for a few years now after ,, guess what...using roundup on the weeds between the flagstones. I used the spray bottle you apply to individual weeds rather than spraying the whole patio, and only one area seems to be badly affected. It is probably the shadiest and therefore dampest patch. Heres hoping for good results image

  • So GLAD to read all the replies through the years. Found this forum when looking for identification of Nostoc and how to ERADICATE it. Most significant, I think ----

    I was going through in my mind what in the world could have caused it, because I had never seen it before. I came to the conclusion that it had something to do with glyphosate (main Roundup ingredient) because, like in a horror movie, it is taking over the areas of my new LIMESTONE gravel driveway that I had sprayed to kill weeds.

    I also believe that Nostoc came in with the limestone gravel because it had never been at my house before. The original drive was an old, worn, rutted, rocky path that had been formed by digging and grading up to the house. I had it re-graded and graveled. The next year I sprayed Roundup and similar products such as Bayer DuraZone for the weeds growing up into the little rocks, especially in the middle that is not worn down by truck tires. The year after that, the Green Blob That Ate My Driveway began its takeover.

    I am dirty and in my work clothes sitting here at the library because I absolutely MUST find some way to eliminate the Nostoc. My driveway is 354 feet long, so that is an awful lot of Nostoc. I had gone over in my mind steps and substances that might kill it and not be toxic to my pets; I have found out here that NONE of them work. Therefore, if I can find washing soda I'm going to try it, and if I can't find it I will use baking soda. I have also bought a piezoelectric fire wand to use with propane canisters to burn weeds; I have seen nothing saying that fire doesn't work, so I might use that in the meantime.

    Thanks for being here. I will let everyone know the results of my now educated battle with Nostoc commune.


  • I have lived here in Virginia for 6 years.  This year, because of an arthritis flare up, I guiltily sprayed Round Up on my gravel drive.  I have been rewarded with a huge growth of what I just found from this thread to be Nostoc.  Never had it before spraying the Round Up.  "Dealing" with one problem led to another.  They should be clear about the causal relationship between this product and this bacterial flareup.  I will try the washing soda cure.  I feel I've gotten what I deserve when I knew I shouldn't have been using the stuff in the first place.

  • hi i am in glasgow and it is all over my slabs

  • Here it is in Cornwall too.  Slippery and prolific .


    Today is July 12, 2017, and I am in Crocker, Missouri, USA. <----- I posted that so a comparison of location can be made if you like.

    As I promised, I am posting everything I have tried and the results. I have had to limit the trials to substances that will not harm the pets or other animals that might happen to walk on the driveway. There is a large enough area of the Nostoc that I can do a bit of each. as the driveway is over 354 feet long.

    I have tried:

    Fire, baking soda, washing soda, 91% isopropyl alcohol, hydrogen peroxide (3%), concentrated rosemary oil with cinnamon oil

    So far, the thing that has worked to make it disappear is FIRE,  burning the dried black particles with my propane torch. The green blobby material has not returned in the burnt areas.. It appears as though burning the wet, green blobs may have worked also, as the material there has turned a sickly, greenish brown, but I won't know until the next rain. I have a propane weed-burning torch that I bought at Lowe's. It doesn't work all that well on the weeds but it eradicates the Nostoc.

    I tried several different modes of washing soda (sodium carbonate). I found it in the grocery store in the laundry detergent aisle. I sifted it over an area and I also scattered it by hand and then wet it in. I will not do that again as YES, it did kill the Nostoc, but NO, it has not gone away and there are still clots of the white powder there that I will have to remove by hand.

    I made a solution of the soda by dissolving as much of it in a gallon of room-temperature water as the water would hold, and that came to 1.75 cups of soda to 1 gallon of water. I sprayed this over an area using the same kind of hand-pump pressure sprayer that one would use to spray the Roundup™ solution on weeds. This coated an area evenly and quickly. It does appear that it has killed the Nostoc, but again, I will not be able to tell until the rain falls again.

    I tried the same with baking soda (sodium BI-carbonate). I can't tell by appearance if the Nostoc is dead. Both the Washing Soda solution and the Baking Soda solution killed the moss that was growing along with the Nostoc in some places, and the Washing Soda solution killed some of the weeds that were re-growing.

    I poured the alcohol on an area; this seems to have killed it. I tried that since Nostoc is a bacterium, not an algae, and alcohol kills bacteria. I want to buy some pure ethanol and set that on fire to see if that works.

    Trying out the hydrogen peroxide was fun. I tried it first on the fresh, newly-grown green blobs, and the bubbling and color change and expansion were entertaining. When it dried, it had the greenish-brown color of dead material. Pouring hydrogen peroxide on dried, crispy, black Nostoc also produced a lot of bubbling and color change. This seems to have made the Nostoc really, most sincerely dead, as the greenish-brown material shrank every day until it disappeared. I might buy a heavier solution of it than 3%. My late husband, when he had a job in the D.C. area cleaning mold and algae out of air conditioning towers, used an industrial-strength hydrogen peroxide to do that job, so I know stronger hydrogen peroxide is available.

    I sprayed on the oils just today so I can't say too much. I bought it in the garden supply area of Lowe's; the label says it will kill plants without hurting animals. I tried it on the small grass sprouts and sprouts of spurges and purslane re-growing in the gravel drive, and they certainly look shriveled and dying to me. I figured I might as well try it on the green, slimy, blobby stuff. Well, on the black stuff anyway; rain has not fallen for nearly a week and all of the Nostoc is black and crispy, except where I tried the various treatments.

    Last edited: 12 July 2017 23:49:16

  • plant pauperplant pauper Posts: 6,234

    I love that you've made it your new hobby Patty. image Thanks for taking the trouble to update us on your latest "speriments".

    Mine diminished a bit when I cut down the Roundup but I'm keeping a close eye for it's return. We've had less rain than normal this year so that has helped but I'm sure I haven't seen the end of this particular beastie!

    Good bacteriocidal thinking with the Peroxide and the IPA. If you're ever looking for a job over here I'll give you an interview! imageimageimage

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