Brewing a cup of field horsetail and fennel tea from Landet Järna. Fields horsetail is an old folk remedy for kidney and bladder troubles, arthritis, bleeding ulcers, and tuberculosis. The Chinese use it to cool fevers and as a remedy for eye inflammations. This is some good stuff and you can harvest it yourself. Harvesting: Pick it in a clean area. Best time to harvest is midsummer when plants are large but still somewhat succulent.