Plant · P-309

Bracken Fern

Pteridium aquilinum

Bracken Fern is one of the most dangerous plants a farm can host: raw leaves and roots deplete vitamin B1, the spores and fronds carry a carcinogen linked to bladder and intestinal cancer, and that toxin is water-soluble enough to turn up in streams and groundwater near where it grows. It is also aggressive and self-sustaining once established, rooting up to ten feet deep and tolerating dry, moist or wet ground across a native range spanning nearly every US state and Canadian province. Despite the toxicity it has real value as a potash-rich fertilizer source, thatch, mulch, dye and tinder - but it needs acid, sandy soil below pH 6.8, and will not grow on limestone or alkaline clay.