Fact Sheet – Horsetail
Horsetail, Equisetum arvense, is a perennial plant also called
`marestail' or `pipeweed'. It is an ancient relic of primeval times -a link
between modern plants and extinct orders. Many of our coal measures are
composed of fossilized remains of immense equisetum-like plants - forests of
which once covered the earth.
Description
Equisetum can be found on all types of soils. It grows from an underground
stem or rhizome, and produces two types of above-ground stem. Brown 'fertile'
stems emerge in the spring and these are topped with a cone-shaped structure
which produces spores. These spores only develop in very moist situations and
are rarely important in a garden situation.
When the fertile stems have died down, brush-like, green
vegetative stems emerge. These are rich in silica so have a tough, wiry feel
(they were once used to scour pots and pans). There are no true leaves; the
characteristic bushy appearance is caused by whorls of branches up the stem.
The underground stems or rhizomes are black in colour. They can penetrate
deeply into the soil and are the main means of spreading. When these stems are
broken-up, individual pieces will regrow very readily in the same way as couch
grass.
Prevention and
control
·
Digging it out: really not a viable
proposition unless you only have a small patch and a lot of time!
·
Shading: as they do not have
significant leaves, horsetails do not compete well with vigorously growing
crops. In the vegetable garden a couple of crops of potatoes, for example would
help to control this weed. A tall growing summer green manure, such as Phacelia
tanacetifolia or buckwheat, might be an alternative. One reference states that
a crop of nasturtiums will smother it out, but this is not something we have
tried. It will take several seasons before the weed is controlled.
·
Hoeing off the tops: another reference
says that continual removing of the tops should kill off the weed in 3-4 years.
A combination of hoeing and growing a smothering crop might well be a good
method to try.
·
Mulching: a heavy,
light-excluding mulch can be used around ornamentals to keep this weed in hand.
Try newspaper or cardboard, covered with woodchips, bark or leafmould to make
it look more attractive.
·
Improve the soil: horsetail tends to
thrive in poor conditions, so improve the soil by adding plenty of organic
matter.
Horsetail tea
Biodynamic growers use horsetail tea to strengthen plants' resistance
to fungal infections. Take ¾ oz dried horsetails and simmer for 30 minutes in 2
pints of rain water. Stand for 24 hours. Make up to 1 gallon, stirring the
mixture for about 15 minutes. This mixture will keep for a couple of weeks.
Spray the plants thoroughly every 10-14 days, starting early in the season. The
later sprayings can be more dilute (making the solution up to as much as 10
gallons) but should always have a pale yellow-green or brown colour and smell
of horsetails.