An Ancient Tail

14 October 2009

In The Garden With the Fluvanna Master Gardeners
By Irene C. Burke - Fluvanna Master Gardener
Fluvanna County Extension Office: 434.591.1950

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At an altitude of 11,000 feet along the eastern shore of Snowmass Lake in the Colorado Rockies, I spotted fist-size mounds of what looked like miniature bamboo; though segmented, the fine reeds were softer, more delicate, densely packed, emerging from velvety patches of moss.

When hunting for bog plants, I found the same curiosity at a water garden nursery in Greenville, Virginia. The "miniature bamboo" proved to be a diminutive form of horsetail (Equisetum scirpoides). Its taller kin, scouring rush horsetail (Equisetum hyemale L.), and itself came home with me that day.

Fossil and friend — Equisetum and all its family members are the sole surviving genus of a class of primitive vascular plants dating to the mid-Devonian period, 350 + million years ago. Though characterized as invasive, it is more rightly termed aggressive, which is surely why it has lasted more than 350 millennia. Silicon crystals within the stems have been used to scour metal containers and utensils to a shine, wooden floors and furniture smooth.

Habits and habitat — The USDA Natural Resources Conservation Service (NRCS) says Equisetum hyemale L. "Usually occurs in wetlands" but occasionally found in non-wetlands... Equisetum lives in northern temperate climates around the globe as well as Mesoamerica.

These two members of the Equisetum family have a lot to recommend to Virginia gardens blessed with sodden clay. Horsetail will grow in no more than 4 inches of water and in my experience retreats from dense dry soil. No amount of sun or shade dampens its vigor but it does not venture into an adjacent bed of Virginia Spiderwort (Tradescantia virginiana). I cannot tell why.

It is a well-behaved companion not overstepping its bounds. Amongst the rushes &mdash astilbe, forget-me-nots, lobelia, and Louisiana iris have all the shelter and moisture they need. In downpours the horsetail slows the torrent, averting the erosion that two years ago swept away precious topsoil.

Water feature &mdash To use as a water feature Equisetum hyemale L. must be controlled in a container with no drainage holes. Monitor for rhizomes escaping over the top. E. scirpoides and E. hyemale L. will restrain themselves from arid ground, though in their search for water they may dig as deeply as 3 feet emerging in moister earth on the other side of powder and dust.

Propagation &mdash To increase, dig up a stalk or two with a small clump of dirt and roots. Transplant to damp soil where theyll establish within a growing season and more likely send up mini spikes from a floppy shoot. Do not confuse these two E. hyemale L. and E. scirpoides with other Equisetum, which flourish in damp woodlands and meadows with a fluffy aspect, some to 6 feet.

Seasonal care — Both remain evergreen; the winter blast will not dampen their vertical habit or emerald hue. What causes some stalks to flop or curve or twist is hard to tell, but it does create artful interest in the garden as well as the vase. In Spring I cut wandering rushes to the ground and clear away debris. That fossils in the garden are not always human helps me stand taller when rising from my muddied knees.

Tip of the Week

Its time to keep a weather eye out for the first fall frost, which comes anywhere from October 10th to the 29th. Refer to our July 8, 2009 column "A Cool Promise" for follow-through on the fall crops planted in July.