Growing Wasabi Plants In Your Yard
Wasabi plants are native perennials found along stream beds in mountain river valleys in Japan. Shade and moderate temperatures are vital to growing wasabi. The plants perform best under bright, moderately shaded locations with northern exposure where daytime temperatures stay between 50 and 70 degrees Fahrenheit. Soil and spacing have a great impact on the long term health and vitality of wasabi plants. Loose, fast-draining soil with a pH between 6.0 and 7.0 is best, although it will also tolerate slightly sandy soil. Amend heavy soil with a 10-inch-thick layer of compost worked into the top 8 to 10 inches of soil to improve its drainage and nutrient content. Mature wasabi plants reach a height of 8 to 18 inches tall with a 12-inch spread. Space them 9 to 12 inches apart to provide adequate space for root production, and spread a 2-inch layer of mildly acidic mulch between them to keep down weeds and conserve soil moisture.
Wasabi plants are not heavy feeders and seldom require fertilizer if planted in rich, organic soil. However, older plants or those in sandier soil may benefit from feeding in mid-spring and midsummer to improve their growth. Side-dress the plants with a 3-inch layer of well-rotted green manure to provide a constant source of nutrients, or apply a slow-release, general purpose fertilizer with an N-P-K number of 10-10-10 or 12-12-12. Apply the fertilizer to pre-moistened soil at a rate of 2 to 2 1/2 pounds per 100 square feet.