Plant of the Week
Latin: Petasites japonicus 'Giganteus'
How could you not be intrigued by a plant listed in the catalog as "Dinosaur
Food"? This plant looks like it’s straight off of the set of one of Steven
Spielberg’s Jurassic Park flicks, complete with giant lizards merrily munching
on its enormous leaves. Unlike the dinosaurs, the Japanese Butterbur is not
likely to become extinct any time soon. The fast-growing herbaceous perennial is
one of the new plants making its way into our gardens.
What makes the Japanese butterbur impressive are the 3-4 foot wide, two-lobed
rounded leaves. The dark green, rough-textured leaves are held aloft on stout
petioles 3-4 feet long that arise from a central crown and form large mounds. A
variegated version is also offered, but its leaves are only about half the size
of the green-leafed selection.
Japanese butterbur is a member of the daisy family. It produces blooms in
late winter, before any foliage appears. Clusters of yellow-green blooms, more
bizarre than beautiful, push from the soil in March like some odd botanical
snow-cone. The plants are dioecious so these vegetatively propagated plants
won’t make seeds without a member of the opposite sex present.
It’s good that the Japanese butterbur does not produce seeds, because this is
a plant that spreads well enough without them. It typically grows in moist
alluvial sites in full sun or partial shade. It produces a network of
pencil-sized rhizomes that spread in all directions from the original plant. It
begins to colonize an extensive area after its second or third year.
Because of its tendency to run, the Japanese butterbur should be planted
where its spread can be closely monitored, or where it can be allowed to roam
more or less at will.
The petioles have been eaten in Japan, but it’s not a common food in modern
Japanese culture. Its large petioles, when dried at the end of the season, are
said to make good walking sticks.
Before we turn a plant such as Japanese butterbur loose in our landscape, it
would behoove all gardeners, acting as caring environmentalists, to carefully
evaluate the possibility of escape. No one wants to be responsible for
introducing the next kudzu.
Like all plants that spread by underground rhizomes, its reach can be limited
by mowing. A mowed swath 10-feet wide will prevent its invasion into unwanted
areas. If no such barrier can be established, make sure it will not move beyond
the limits of your own property.
In the garden, the enormous foliage of Japanese butterbur creates a tropical,
exotic feel. Use it in the wild garden or as a background planting for plants
such as hostas and other shade lovers.
The plant grows most quickly in deep, fertile sites, but it’s also tolerant
of heavy clay soil. It’s sensitive to dry soils and wilts quickly when water
becomes short. It grows well in medium shade or full sun; but in sunny sites,
some protection from strong wind is advisable to prevent injury to the large
By: Gerald Klingaman, retired
Extension News -
July 20, 2001
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