Giant Horsetail
Equisetum telmateia

Family: Equisetaceae

What it is like

Equisetum species - horsetail family are Creeping, perenial, Branching rootstocks, rooted at the nodes. The Arial stems may be annual or Perennial, are cylindrical, fluted, simple or with whorled branches at the jointed nodes. The internodes are usually hollow. The Surfaces of the stems are covered with Silica. The Cones are terminal.

Equisetum telmateia is a PERENNIAL growing to 2 m (6ft 7in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower in March, and the seeds ripen in April. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 2

Where it is found

Damp shady banks etc, to 350 metres.

Europe, including Britain, from Sweden south and east to N. Africa and W. Asia, N.W. N. America.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 1

Strobil (the fertile shoots in spring) - raw or cooked. The tough outer fibres are peeled off, or can be chewed and then discarded. The vegetative shoots, produced from late spring onwards, were occasionally cleaned of their leaves, sheathing and branches and then eaten by native North American Indians, but only when very young and tightly compacted. Root - cooked.

Stem: this often intergrades into leaves.

Medicine

Rating: 1

The plant is astringent and diuretic. A decoction has been used to treat 'stoppage of urine'. A poultice of the rough leaves and stems is applied to cuts and sores.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.

Other

Rating: 3

The stems are very rich in silica. They are used for scouring and polishing metal and as a fine sandpaper. The stems are first bleached by repeated wetting and drying in the sun. They can also be used as a polish for wooden floors and furniture. The infused stem is an effective fungicide against mildew, mint rust and blackspot on roses. It also makes a good liquid feed. Used as a hair rinse it can eliminate fleas, lice and mites. The black roots have been used for imbrication on coiled baskets.

Basketry: Plant used in making baskets and other items such as chairs. Includes plants that are only used as an ornamental addition.

Fungicide: Arrests the growth of, or kills, fungi.

Hair: Plants used as hair shampoos, tonics, to treat balding etc.

Liquid feed: Plants that can be used to make a liquid fertilizer.

Polish: Plants used to give a shine to metals, wood etc.

Sandpaper: Plants used to smooth rough wooden surfaces by means of abrasion.

Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.

How it is grown

Prefers a moist soil with a pH between 6.5 and 7.5. Plants are hardy to about -30°c. Plants have a deep and penetrating root system and can be invasive. If grown in the garden they are best kept in bounds by planting them in a large container which can be sunk into the ground.

Propagating it: Spores - best collected as soon as they are ripe in the spring and surface-sown immediately on a sterile compost. Keep moist and pot up as soon as the plants are large enough to handle. Very difficult. Division. The plants usually spread very freely when well sited and should not really need any assistance.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge; Cultivated Beds;

Habit: Perennial

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Large quantities of the plant can be toxic. This is because it contains the enzyme thiaminase, a substance that can rob the body of the vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase. The plant also contains equisetic acid - see the notes on medicinal uses for more information.

Its other names

Local names

Synonyms

E. maximum. auct.