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Recently, I was fortunate to be performing some contract arborist work at Wake Atoll when ecologist John Gilardi introduced me to a new plant.
“Here Heidi, taste this,” he said, handing me some leaves from a little plant. “We call it ‘wasabi plant.’ ”
We were walking to the bird meadow on one of the islets of Wake Atoll at sunset. It was very hot with no wind; water barely quenched our thirst.
At first the leaves just tasted a bit green and refreshing. Then my mouth got happy, almost exploding with a definite wasabi taste. I got all excited, asking him more about the plant while I took some pictures of it. It looked like a weed, but with papery transparent seeds. It was one of many interesting native plants on the remote atoll.
When I got back home, I did some research about this plant, which scientists call Lepidium. Another name for it is garden cress. Here in Hawaii, we have one that is a weed and one that is native.
The non-native one is L. latifolium, and it’s been here a long time. Dr. William Hildebrand mentioned it in his 1888 publication, “Flora of the Hawaiian Islands.” The physician and botanist grew an extensive garden that would become Foster Botanical Garden.
Our native Hawaiian wasabi plant, known to scientists as Lepidium bidentatum var. o-waihiense, has many Hawaiian names: kunana, naunau, anaunau and anounou; and lots of English ones too: Kunana pepperwort, peppergrass, pepperweed and scurvy grass.
I wondered if it’s high in vitamin C because of the last moniker.
Turns out it is a good source of vitamin C, A and K, as well as calcium, iron and magnesium, according to the U.S. Department of Agriculture.
The plant is endemic to all the Hawaiian Islands except Kahoolawe and Niihau, and is found on Kure and Midway atolls and some of the other islets of the Papahanaumokuakea Marine National Monument, or the northwest Hawaiian Islands.
It is in the Brassicaceae plant family, along with turnips or daikon, cabbage, mustard greens and our favorite: wasabi (Eutrema japonicum).
After learning about the plant, I thought it would be fun to grow and give to my fellow gardening gourmets.
So far it hasn’t been easy to grow, but I endeavor to persevere. I find it growing in surprising places and have been trying to figure out its ideal habitat.
Sometimes it’s in a lawn, like on the University of Hawaii at Manoa campus or at Kapiolani Park. Sometimes it’s by the beach.
Visiting Sweet Land Farm in Waialua with my horticulture buddy Rachel Morton, we found it outside the barn where keiki goats were being nurtured. I got all excited and had Morton and farm co-owner Mary Bello taste it.
“Ono, yea? And isn’t it a cute plant?” I said. Imagine if we grow more and had the goats eat it. Would their milk be wasabi-flavored?
We collected some to grow and so far, so good. I think because it’s a very xeric, or drought-tolerant, plant, it must have deep and far-spreading roots.
Growing it from seeds is a good option. Horticulture with native Hawaiian plants is so much fun and a great challenge for gardeners. We always learn something by growing plants and observing our gardens and nature in general.
Has anyone else tried to grow this?
One reference suggested that it would grow best in an herb garden, as compared to a general landscape. It really does look like a weed until you get up close and see what a pretty plant it is.
I potted mine up in a mixture of good potting soil and coarse cinder. Morton planted hers directly in the soil in her mother’s herb garden in a sunny spot up in Tantalus. We shall see how it all grows!
Heidi Bornhorst is a sustainable landscape consultant specializing in native, xeric and edible gardens. Reach her at heidibornhorst@gmail.com.
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