Last updated on October 23rd, 2023 at 08:40 pm
You can grow wasabi plants yourself and make your own wasabi paste. We explain how to plant wasabi and give you tips on care, harvesting and preparation.
Wasabi is a plant from the cruciferous family. Although wasabi is also known as “Japanese horseradish” because of its pungency, it is not closely related to European horseradish. In Japanese cuisine, it is mainly the root that is used to make a spicy seasoning paste. It goes well with homemade sushi, for example.
You can also eat the striking, round to heart-shaped leaves of the wasabi plant. Their flavor is much milder than that of the root and they make a good ingredient for salads.
Wasabi perennials grow between 20 and 60 centimeters tall. In their country of origin, Japan, they grow at cool temperatures of eight to 20 degrees, especially on river banks. These specific conditions exist in Europe only to a limited extent. Growing wasabi outdoors is therefore complicated in this country. Nevertheless, you can plant wasabi in a pot and overwinter it indoors.
Contents
Planting wasabi: Here’s how to do it
If you want to plant wasabi, you have the choice between seeds and seedlings. You can sow wasabi seeds in spring, but they are often difficult to obtain and, as already described, rather demanding to grow. It is therefore more recommended to use young plants.
Wasabi can only be planted in pots in this country. This is mainly because wasabi plants, despite their preference for cooler temperatures, are not frost-hardy and would not survive European winter temperatures. Choose large planters with saucers for the young plants. It is also important that you use the right plant soil. It should be
- rich in nutrients,
- rich in humus
- and loamy.
From a sustainable perspective, you should also use peat-free soil. In this way, you contribute to climate and species protection, since peat extraction destroys bogs.
After you have placed the young plants in the tubs, you should place them in a cool, semi-shaded location without direct sunlight. The temperature should be around 15 to 20 degrees Celsius and as stable as possible.
Care tips for wasabi plants
Keep the soil in the containers evenly moist after planting your wasabi. However, make sure that the roots are not permanently submerged in water during the growth phase. The saucers of the containers should always be filled with a finger’s width of water.
In winter, you should bring the wasabi plants indoors and store them in a cool, dark room. Temperatures just above zero degrees are ideal – but they should not drop below freezing. If you have a conservatory or an unheated greenhouse, you can also overwinter the young plants there in brighter light conditions.
Apart from regular watering and the right temperature, there is little you need to do after planting wasabi. However, you will need some patience, as the young plants grow very slowly. You can speed up the process by occasionally mixing some liquid organic fertilizer into the water. Also, check the plants from time to time for pests. Wasabi is susceptible to aphids, but also to slugs. Learn how to protect your wasabi perennials from these plant pests here: Fighting Aphids: Helpful Home Remedies and Fighting Slugs in the Garden: Tips and Natural Remedies.
Harvesting and propagating wasabi after planting
Once you’ve planted your wasabi perennial and it’s thriving, you can harvest wasabi leaves year-round. It can take up to 18 months for wasabi roots to be ready for harvest. They will have a length of about 15 centimeters. You can carefully remove the fully grown root from the pot together with the root ball, free it from the substrate and wash it thoroughly. If you do not plan to use the root immediately, you can put it in a jar, cover it with water and store it in the refrigerator. It will keep there for up to four weeks.
You can also easily propagate wasabi by cutting the root rhizome in half. Then plant the two halves of the wasabi root in two separate pots and care for them as described above.
Recipe: Make your own wasabi paste
Ingredients:
50 gwasabi root
1 tablespoon rice vinegar
1 pinch(s) of salt
Preparation
- Wash the wasabi root and peel it.
- Grate the root with a kitchen grater. Use the side of the grater that has holes on the outside and spiky edges. Alternatively, you can puree the wasabi in a blender.