In our last article in this series of posts about biodynamic ferments and peppering, I explained how to make and use a problem weed ferment.  But we can use weeds in ferments for much more than just keeping a challenging one in check.

Weeds are naturally full of nutrients, and when they decompose through fermentation or composting those nutrients become available.  Using the problem weed ferment methodology, you can use the following weeds to make specific mineral-enriched teas:

Blackberry Chlorine
Bracken Potassium
Broom Magnesium, sulphur
Chicory Iron, Calcium, Copper
Cleavers Iodine, Calcium, Copper, Silica, Sodium
Comfrey Iron, Chlorine, Potassium, Sodium
Dandelion Calcium, Copper, Iron, Magnesium, Potassium, Silica
Dock Iron
Duckweed Copper, Boron, Zinc, Phosphorus
Fennel Copper, Potassium, Sodium, Sulphur
Gorse Phosphorus
Inkweed Potassium
Nettles Iron, Potassium, Sodium, Sulphur
Plantain Calcium, Sulphur, Potassium
Oak Calcium
Ragwort Copper
Shepherd’s Purse Calcium, Sodium, Sulphur
Sorrel Calcium, Phosphorus
Spanish Needle (Bidens bipinnata) Helps regulate soluble Potassium & Nitrogen
Thistles Nitrogen, Copper, Silica
Yarrow Sulphur, Potassium
Willow Calcium


The following table also provides the ‘ingredients’ for ferments that address specific mineral deficiencies in the soil:

Soil Nutrients Needed Materials Needed Requirement for 200 litres Maturing Period Best Dilution Ratio
Calcium   (Ca)
Nitrogen   (N)
Cow dung
Legumes, foliage
65 kg
2/3 barrel
3 months
2 months
Potassium   (K) Wood Ash
Yarrow plant
25 kg
2/3 barrel
3 months
3 months
Phosphorous(P) Rock Phosphate
10 kg
2/3 barrel
3 months
3 months
Micro-nutrients Fish meals
12.5 kg
1/2 barrel
6 months
4 months
Iron   (Fe) Stinging Nettle 2/3 barrel 2 months 1:9
Insecticide Neem Cake
Neem Leaf
20 kg
20 kg
1/3 barrel
3 months
3 months
3 months
Fungicide Casurania

Beef wood

Restios (Restionaceae)

2/3 barrel 4 months 1:10