Growing Wasabi plants outdoors will commence with the starts being sold ‘bare-root’, thus negating the necessity for shipping them in compost-containing pots, which would incur higher costs. Throughout the transit process, the plant relies on the rhizome for sustenance and energy, facilitating the continued growth of roots and stems from the rhizome.
A well-established plant will produce large heart-shaped leaves about 60 cm high and a metre wide. It does not require much sunlight, which is why Ireland is a great place to grow Wasabi.
During the growing cycle, the leaves die back in winter because all the energy is transferred to the rhizome. The rhizome is a swollen stem, sometimes referred to as wasabi root, that contains essential nutrients to help the plant through the winter. The plant will continue to grow through the seasons.
Growing wasabi plants outdoors can survive temperatures down to –5ºC, and caring for them requires patience and determination. However, the reward is great because, after harvesting, you can grate your fresh wasabi from the rhizomes.
During the 2-year growing cycle, you will be able to enjoy Wasabi Leaves, Stems and Flowers, which are delicious and can be picked throughout spring and summer. They can be used to make a delicious addition to your salad!
When you receive the wasabi plant start, you should plant it into at least a 9 L pot with soil, compost, and grit/pea shingle (9:5:1). Also, provide plenty of shading to protect the plant from the extremes of weather patterns. In addition, when planting the wasabi starts, make sure you use fertile soil and plenty of drainage to avoid root rot. Remember, Wasabi likes lots of water but dislikes sitting in puddles.
Furthermore, plant the wasabi so that the growing medium is slightly below the crown. This facilitates the growth of new leaves.