Monday, October 8, 2012

Wapato, cultivating native tubers

Robin egg like Wapato tubers from Dees Slough
Shoreward, Cottonwood and Western Birch blaze gold against the clear blue skies and slopeward, Maples burn fleeting red hues amongst the more temperate evergreens. It is the season of contrast and each day of sunshine is preciously coveted by veterans of our gloomy Cascadian winters. When will the weather turn? Our first heavy frosts signal the beginning of the season for harvesting the tubers of Wapato (Sagittaria latifolia) and Jack Frost’s pigmented associate does not fail to notice Wapato’s arrow shaped leaves, painting them a delicate yellow. For Wapato, it is the season for attending to future growth, and rhizomes that have stretched horizontally through soft silt and muck all summer now squirrel away the last golden rays of sunshine into egg shaped tubers deep beneath the mud. From these tubers will hatch the promise of Wapato’s future when the sun shines anew next spring.

Wapato seed clusters easily shatter into hundred of seeds when ripe
Not all is invested in the tubers. As cool weather drives away Wapato’s final pigments and the entire emergent body of the plant prepares to wither to the detrital depths, the spherical seed clusters shatter into hundreds of embryonic vessels that disseminate across the water’s surface until they strike sticky bare sediment suitable for growing a new generation of roots.

A healthy patch of Wapato in the Coeur d'Alene watershed
Prior to contact, Wapato grew abundantly along the lower reaches of the Fraser and Columbia Rivers as well as in the Coeur d’Alene and Yakima Rivers in the interior. Wapato was managed in carefully tended family garden patches and gathered throughout the fall and winter as a staple root vegetable. Sto:lo elder Ralph George told me that he remembers raking away the detritus from sloughs near Chilliwack BC so that the Wapato would grow better, and Melissa Darby writes of family owned patches being carefully market and cleared of large woody debris by the Chinook near Sauvie Island (formerly known as Wapato Island) on the Lower Columbia (see Keeping it Living). During the winter of 1805-1806, Lewis and Clark noted that Wapato was the “principal article of trade” along the Columbia. In 2007 archaeologists from Simon Fraser University excavated a 3000 year old Wapato garden along the shores of the Fraser River. They discovered a conspicuous rock layer at the bottom of the Wapato bed that likely limited the depth that the tubers could burrow, making them easier to harvest during the cold winter months. Unfortunately habitat loss due to the construction of dams and dikes as well as predation from introduced carp have severely restricted the abundance of Wapato throughout much of its former Northwest range. Native American use of Wapato for food has suffered a similar fate due to loss of access to the tubers and the hyper-availability of introduced foods.

Today, Indigenous people are working to revitalize this once important root vegetable. The Coeur d’Alene host an annual Wapato digging festival at Heyburn State Park. The Yakama are working to remove dikes and restore Wapato habitat (see here for more details), and Roma Leon of the Katzie First Nation has started teaching people how to harvest the tubers from the Lower Fraser River valley (see here for more details).

Amongst driftwood Wapato can be difficult to harvest
I too want to be part of the restoration of such a valuable food source, and last weekend Katrina and I gathered some Wapato tubers to transplant to my dad’s pond and experiment with other methods of cultivation. We chose Dees Slough as our source population and carefully extracted about 1 dozen tubers from the cool dark muck. The mud was thick with branches and driftwood making it impossible to employ the “wapa-tip-toeing” method of churning the soil with your feet and waiting for the tubers to float to the surface. Rather, we tickled the roots of the plants until we located a rhizome, and then slid our fingers along the bottom of the rhizome, loosening the soil around it by wiggling our thumb and forefinger and raking away the loose soil with our other hand until we traveled the 6-18 inches of rhizome to the tuber. This method may be best called “wapa-tickle-hoeing.”

I planted half the tubers in my dad’s pond and used wire tomato trellises to mark their location and protect them from hungry ducks. I also cast a generous layer of Wapato seeds throughout the area. In the wild, Wapato doesn’t generally grow in stagnant water, but I am curious to see if my transplanted tubers will come up next year. Wapato seeds evidently take 2 years to germinate. I planted the remainder of the tubers in a 30 gallon plastic tub (a “wapatote”) that was half filled with loose silt/organic soil and topped off with water. I buried the tote in the ground so that it won’t freeze solid this winter and plan on circulating the water with a pump once they start to grow next spring. After I establish a healthy population, I can then study the how the yearly process of disturbing the soil to harvest tubers affects their size and abundance.

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