San Marcos GrowersSan Marcos Growers
New User?
Wholesale Login
Enter Password
Home Products Purchase Gardens About Us Resources Contact Us
 Web Site Search
Plant Database
Search by Plant Name
  General Plant Info
Search for any word
  Advanced Search >>
Search by size, origins,
color, cultural needs, etc.
Site Map
Retail Locator
Plant Listings

  for JULY

 Weather Station

Products > Equisetum myriochaetum
Equisetum myriochaetum - Giant Horsetail

[2nd Image]
Habit and Cultural Information
Category: Grass-like
Family: Equisetaceae (Horsetails)
Origin: Mexico (North America)
Evergreen: Yes
Flower Color: NA
Bloomtime: Not Significant
Synonyms: [E. mexicanum]
Height: 6-10 feet
Width: Running
Exposure: Sun or Shade
Irrigation (H2O Info): High Water Needs
Winter Hardiness: 15-20 F
May be Poisonous  (More Info): Yes
Equisetum myriochaetum (Giant Horsetail) - This prehistoric remnant is among the tallest of the living horsetails. Given optimum conditions, which includes a frost free location with ample water and rich soil, this subtropical plant is evergreen and can grow to an astonishing 15 feet tall and in some reported cases to 24 feet although plants attaining this height were likely stems supported by other vegetation. From underground rhizomes are produced 1/2 inch wide hollow aerial stems that arise at tight intervals, forming dense colonies. The stems appear jointed with fine hair like green leaves in whorls sometimes accompanied by side branches that both emerge from sheaths at the stem nodes. Plant in full sun to light shade in a rich soil and keep moist. Best in a container or with an area protected by a deep root barrier to check spread of the rhizomes. This species is found in Nicaragua, Costa Rica, Colombia, Venezuela, Ecuador, Peru and Mexico (Nayarit, Jalisco, Colima, Michoacan, Guerrero, Mexico State, Oaxaca, Puebla, Veracruz, Hidalgo, San Luis Potosi, Nuevo Leon, Chiapas). We received our stock on this plant from Monterey Bay Nursery who received it from the University of California, Berkeley - their accession listed it as collected in Veracruz, Mexico. Horsetails show promise as ground covers for dikes, road cuts, abandoned strip mines and other bare areas. They tend to absorb heavy metals, and so may be useful as biological monitors of water or soil contamination by zinc, cadmium and lead. Note, however, that horsetails cause a serious poisoning, called equisetosis, in horses. For this reason it may not be suitable for certain farm ponds. Name origin: 'equus', Latin for "horse" and 'setum', Latin for "bristle".  Information on this page is based on research conducted in our nursery library, from online sources, as well as from observations made of this plant as it grows in our nursery, in the nursery's garden and in other gardens where we have observed it. We also will incorporate comments received from others and welcome getting feedback of any kind from those who have additional information, particularly if this information is contrary to what we have written or includes additional cultural tips would aid others in growing Equisetum myriochaetum.