Woad--Sarah's
Natural Colour
I've been growing the natural
dye, woad, since 2000. In 2006 I grew woad at Joybilee Farm
for my first
science fair project. I had a nil indigo yield when I tried
to
dye directly with the leaves using the method in Rita Buchanan's book,
"A Dyer's Garden" (Interweave Press), a process originally suggested by
Beijerinck in 1900.
In 2007, my project competed at the Canada Wide Science Fair (Truro,
Nova Scotia) in Biochemistry and Pharmeceutical Sciences. I
determined that natural indigo was most colour fast when dyeing using
repeated vattings and oxidizations to lay down a dark colour, rather
than a single dip in a strong vat.
My 2007 abstract: (pdf) "Woad is Me, finding a permanent blue from
sustainably grown indigo"
I continued to grow woad
altering the growing conditions in an attempt to enhance the indigo
production in my harsh, zone 3, marginal growing conditions.
I
also changed my extraction method and found that the indigo yield was
greatly increased. In fact, my woad indigo yields were
essentially the same as the indigo yields obtained on prime agricutural
land in current scientific studies in Europe, but I am growing on land
that is considered marginal range land and receives summer frost.
I grow my natural dyes organically, unlike the scientific
studies.
In 2008 I took Phase 2 of my science fair project, on growing natural
woad
indigo and extracting its dye, to the Canada Wide Science Fair
(Ottawa).
My 2008
abstract: (pdf) "Woad to a sustainable blue colourant, Phase 2"
I isolated two
high producing strains of woad (pastel) and have begun
hybridizing to enhance the indigo yield in my harsh growing conditions.
2008, Phase 3 of my project, I found that the indigo yields of
plants selected for vigour in my harsh climate, had doubled
their
indigo yield -- averaging 4 grams per kg. of leaves. Tropical
indigo averages 5 gms of pigment per kg. of leaves so this result is
encouraging. Especially in light of the fact that
my woad
is growing on range land which is unfit for normal crop
agriculture, due to its short growing season, high elevation and incidence of summer frost.
My 2009 abstract: "Woad to a sustainable
blue, Phase 3"
In the next two years I hope to investigate the growing conditions
and the variables of the extraction method that enhance natural indigo
yields
in woad. I am also comparing the phenotype and indigo
production
of several landrace strains of woad, including a North American,
1 French, 2 British and 1 Norwegian strain. Finally, I hope
to
hybridize a high yielding strain of woad that will yield indigo in
temperate, marginal conditions at the same rate as tropical
indigo in its ideal climate zone, typically 5 gm of indigo per 1 kg. of
leaves. My current extraction method gives between 3 and 7
grams of indigo per kg. of leaves, of varying purity.
Woad isn't just a natural dye plant. It is also being
investigated for
its healing properties. It is anti-fungal, anti-viral,
anti-inflammatory and anti-tumour. It is an ingredient in a
medicine for HIV/AIDS. It has more gluco-brassicin, a potent
tumour fighting plant extract, than broccoli,
and this property can be enhanced through leaf wounding, and it is
being investigated as a cancer treatment.
New: Woad Workshops -
Learn more about woad at our woad workshop:
Growing a sustainable blue -- The Woad Plant and its dye --
taught by Sarah and Christine Dalziel at Joybilee Farm in Greenwood, B.C. Canada
Website
credits: Thank you to my mom, Christine Dalziel, for designing
and setting up the templates on this website. Writing is the work
and copyright of Sarah Dalziel; Photographs are the work and copyright
of Sarah Dalziel except where Sarah is in the picture -- those
photographs were taken by Christine Dalziel.
Webmaster: Sarah Dalziel.
©
2007 - 2009 Sarah Dalziel
