150 Seeds Wasabi Seeds Vegetable Seeds for planting Bonsai - DIY Home Garden Plants. Wasabi or Japanese horseradish is a plant of the family Brassicaceae, which also includes horseradish and mustard in other genera. The plant is native to Japan, the Russian Far East including Sakhalin, and the Korean Peninsula. It grows naturally along stream beds in mountain river valleys in Japan. Nagano is one of the best places in the world to cultivate wasabi and try it fresh. This place is huge! Daio has covered an entire river bed to give the wasabi plant shade. Wasabi plants grow leaves year round and you can keep harvesting leaves every 6 -8 weeks and enjoy wasabi greens during the whole 15 months to two years that you are growing the plant stalks. The highest quality wasabi, whose translated name is mountain hollyhock (also known as sawa wasabi), thrives on cool water. It grows along the edges of cold mountain streams.