By Mary Gutierrez
gardeners may cringe at the suggestion that horsetail (Equisetum spp.) is anything but a rank
weed. As it
begins poking its feathery stalks through the soil in my garden beds each
spring, I’ll admit I have a hard time maintaining objectivity.
One problem with my horsetail is that it’s the wrong kind. Instead of the
tall, elegant hollow
knobby joints, mine is the fluffy, feathery kind. What’s the difference? I’m
glad you asked…
genus name, Equisetum, is from the Latin equus, horse, and seta, bristle. The name refers to the coarse
roots of Equisetum fluviatile, the water horsetail, not the
feathery green foliage you see growing in spring.
genus Equisetum is then split into two
subgenera: Equisetum and Hippochaete.
Members of subgenus Equisetum have thin branches emerging from the
knobby nodes along their stems. What I have in my garden is the feathery Equisetum
arvense, a member of this subgenus.
of subgenus Hippochaete are commonly called scouring rushes, and
have no branches. These are the horsetails with enough architectural presence to
grace the water garden or a container.
Exactly, Are They?
common name for the equisetums is horsetail fern. Indeed, both plants share a common reproductive strategy: they produce spores
instead of seeds.
Horsetails use this primitive method of
reproduction because they are, indeed, ancient. Equisetum
is the only surviving genus of the class Sphenopsida—a class that included tree-sized
horsetails during the Carboniferous period 300 million years ago.
can imagine a prehistoric forest of Douglas fir-sized horsetails growing in a
humid, swampy environment. Earlier this year, I wrote a story about how heron-sized dragonflies populated the earth 250 million
years ago. Just as dragonflies perch on stems of horsetail today, in my mind’s
eye I can see those giant insects flitting through a horsetail forest.
prehistoric garden would also be populated by a few other plants still in
existence. The cycads—often confused with palms—came along just after the huge
horsetails, and were contemporaries of the ginkgo, monkey puzzle (Araucaria
spp.), and tree-sized mosses.
on which source you consult, there are somewhere around 20 Equisetum species in the world today.
A few of them are available to
gardeners to grow as a water garden accent or a container specimen. The
popular ones belong to the jointed-grass group in subgenus Hippochaete.
species of horsetails are most commonly available for sale at nurseries: Equisetum
hyemale, the horsetail rush, which grows two to
three feet tall; and Equisetum
scorpioides, or dwarf
horsetail, which grows to just 10 inches tall.
love riverbanks and swampy areas, so are perfectly adapted to the backyard
pond. If grown in the pond, keep the crown of the plant above
the water’s surface. Any nursery person worth their salt will tell you that equisetum
is a great marginal plant—just keep it confined to a pot. Horsetail can spread
very rapidly and is classified as an invasive plant in some parts of the
country, so don't sink its roots into open soil.
I think a great
way to display equisetum is in a striking pot sited on
the banks of your water garden. It makes a dramatic focal point at the pond’s
edge. When your friends come over to admire your garden and they ask about the
distinctive plant growing by the pond, you’ll have lots to tell! NWGN