BioFertilizer Recipe #2: Lime Sulphur (Caldo Sulfocalcico)

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Eugenio Gras, BioFertiliser maestro!

**Note: Please wear safety gear when making & using this mix as it is caustic to the skin. Ouch! Good for its intended purposes, though.

Okay so this one is not strictly a fertilizer (like our Biofertilizer recipe #1), it’s more an anti-fungal preparation. Still, anti-fungicides are something our agriculture pours millions, if not billions of dollars into every year. Some of the food you eat today will definitely have had anti-fungicides applied during the growing cycle.

So can you make a natural, low-cost version, which has no crazy side-effects? Yes, you can! And we did. While lots of people watched, who can now go home and make their own.

Eugenio Gras explaining how to make the Lime Sulphur

This preparation was taught to us by the blisteringly awesome Eugenio Gras from COAS in Mexico. COAS works with Campesina farmers in latin america to improve their crops and livelihoods, and to keep them on their land. COAS does this by figuring out ways to do organic agriculture which is decidedly cheaper for the farmer than conventional agriculture.

And they’ve done this partly by devising ways to make organic DIY versions of fertilizers that make plants grow better with more nutritional density, that improves the soils and prevents toxic buildup in the land, the rivers and in the farmers themselves. Everybody wins! Except the conventional fertilizer companies. They don’t win at all.

A situation where a farmer can make their own fertilizer cheaply on their own farm, is a very, very big deal. Especially when you consider that most conventional farmers the world over frequently take out major loans just to be able to buy the fertilizer they need to grow the crops that you and I eat every day.

Add to that a set of DIY fertilizers which give better yields than conventional fertilizers, and are organic (and not toxic to the soil life, the land, the farmer’s family, etc etc) to boot, and you’ve got a very, very, very big deal. I suppose that’s why 60 farmers showed up at our farm from all over Australia to learn how to make BioFertilizers.

This preventative anti-fungicide is designed for agricultural-scale use. In your garden, you could use any number of funky organic anti-fungal preparations (like garlic spray). However, making your own garlic spray for 100 acres (or more) of crops isn’t something that’s very doable – the volumes of ingredients necessary are just too great, and would be prohibitively expensive and time consuming to make.

And that’s where preparations like this Lime Sulphur comes in. A simple, cheap, non-toxic anti-fungicide that anyone can make with basic ingredients, at a scale appropriate for agriculture.

Water boiling in it’s drum, on bricks above the fire, with loose lid
Eugenio weighs the lime for the mix
Eugenio adds the lime, sulphur and ash mix to the boiling water
Paul Taylor stirs the brew
Lime Sulphur after being boiled for an hour – ready to use
Eugenio shows the funnel, covered in mesh to catch any remaining sediment
Filling up the bottle
Eugenio Gras with a bottle of Lime Sulphur preparation, ready to dilute and use!


This lime sulphur preparation is generally diluted to 2-3 parts to 100 parts water (so very weak), and sprayed out over crops, trees or any other foliage as a preventative anti-fungal. Eugenio recommends using it in concert with BioFertiliser recipe #1 (or a variation thereof) and phosfito, something I’ll share with you shortly. See also our BioFertilizer recipe #1 which worked splendidly, smells great and is about to be applied to our plants.

Some resources:

  • Our past and future adventures with BioFertilizer
  • Photos of our BioFertile Farms course with Eugenio Gras and Paul Taylor in October 2010
  • Eugenio Gras’s photos of COAS’s work
  • Resources relating to this course (including some of COAS’s biofertilizer recipes) and an ongoing discussion on Biofertilizers in english at

Eugenio Gras was is Australia in 2010 as part of the Regenerative Agriculture Workshop series, which our BioFertile Farms workshop was a part of. Many thanks to Eugenio Gras and Paul Taylor for coming to Milkwood to share their knowledge with us all at this workshop, and also to all the folks who came to learn from near and far.

We’re hoping to bring Eugenio back next year for more Biofertilizer antics, and also to teach us some Chromatography, a technique for cheaply assessing your soil in an ongoing way. If you’re interested in future BioFert events we’ll be doing, jump on our mailing list here.

***NOTE: Biofertilizers, like anything you put on your plants and soil, should be handled carefully and used appropriately.

Next up, the burning of the bones to make phosfito! Viva la BioFertilizer!

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17 responses to “BioFertilizer Recipe #2: Lime Sulphur (Caldo Sulfocalcico)

  1. “Biofertilizers, like anything you put on your plants and soil, should be handled carefully and used appropriately”…
    Eugenio did say that using this product was not suitable for cucurbits and recommended to use a 100:1 water/bi-carb soda mix for powdery mildew.
    In researching commercial lime/sulpher mixes which seem to be very similar to this product I found that its use on sulphur sensitive varieties of apples like Delicious and Cox’s Orange Pippen is not recommended.
    A 50ml/L is recommened for stonefruit prior to budswell, 50ml/L at late budwell for other apples and 100ml/L close to budburst for grapes. Used for leaf curl, mites, rust and scale.
    For citrus in winter use a 50ml/L app and a 25ml/L in summer after peal fall for scale, rusts and mites.
    Spraying lime/sulphur after late green tip stage will restrict growth and depress yields.
    This is a spray for winter dormant fungi/pests and shouldnt be repeated on pests shown to have an immunity to the application,it may become the dominant disease. Better to try something else.
    Most importantly this should not be used at the same time as the biofertiliser as this product will kill the microbes and friendly organisms in the biofertilser.
    I do hope this doesn’t confuse the benefits of this biofertiliser, and is just a word of precaution.

    1. Nice one, David! Yes we do need a follow-up post on the exact uses of bioferts… the plan is to outline the three techniques we’ve learnt thus far, then get into the how and why of application… many thanks for your first-hand knowledge and thoughts…

  2. you should DEFINITELY be wearing some safety gear, and add PROMINENT warnings to this article, that stuff is caustic as all hell.

    anybody using this should read the MSDS at least.

    and non toxic? msds says it makes hydrogen sulfide when you ingest it.

    also, you can actually buy this prepared. idk if its cheaper or more efficient, will depend on what kind of ag supply is around.

    am i qualified to tell you this? yes. i sprayed many hundreds of gallons of it on organic apples last summer. i also got a tiny drop in my eye (yes, ouch), and melted my pants with the concentrate.

  3. This is an excellent thing!

    In the (Matamoros) Guerra Contra Sarna we use sulfuated lime on dogs with sarcoptic mange (“roña” or “sarna”). 1 bath per 5 days. Wonderful results.


  4. I have 20 acres of pecan trees. The commercial fungicides I have used in the past are very expensive and do not always work.
    2 questions: how often should I spray through the summer? Where can I obtain a good source of lime?

  5. A 1910 “Chemical Investigation of Best Conditions for Making the Lime-Sulfur Wash” gives its optimum recipe as:

    80 lb pure sulfur
    36 lb pure quicklime
    50 gal water

    If the sulfur or lime is not pure, use more of it.

    If using hydrated lime, use 1/3 more of it.

    Boil outdoor for an hour, adding hot water to keep the level up; keep it stirred. plenty.

    A hydrometer is useful for measuring the density of the solution, and getting an idea of its sulfur concentration.

  6. This stuff works wonders on mangy dogs very true! We tried everything and now purchase a very popular dog mix with the lime and sulfur, thanks for the homemade version of this oh by the way sulfur also clears up acne seek medical advise when using it on humans

  7. Although the commercial product is affordable at $90/gallon, that is 120 times the cost of the ingredients. So if you are making plenty of it, it might be best to make it ourself.

    I use builders/hydrated lime. I get 90% sulfur from a fertiliser warehouse for about $18 per 50-lb bag. It is in clay pellets. They stand up too well to the boiling, so they need to be ground down first.

    The New York recipe requires that water be added from time to time. Make sure to add enough to fully compensate for evaporation. My tendency has been to not add enough.

    The lime must first be boiled some before sulfur can bond with it in water. So there might be some justification for withholding the sulfur until that time, and then to add the sulfur, with the (1 hour) timing beginning once boiling resumes.

    Boil outdoor. A windy day is not so good. Use a long stirring stick, like a boat paddle so you can stay away from the smoke and sulfur fumes

    Dilute about 1:25 to put on animals. Don’t get it in the animal’s eyes. Have water handy to rinse the eyes. When he shakes his head it can fly off the ears into your eyes.

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