When
the ground is moist and weeds are visible, the ‘Removal
of Individual Plants’ becomes a simple and immediate
option, always selective and much more competitive than
people realize.
Optimum
times for initiating RIP vary with latitude, degree
of site exposure, type and degree of grazing, but all
clearances should be started well before the growing
season. The months of May, June, July, are for ‘follow-up’,
or special tasks involving both 1st & 2nd
ragwort plants (see note below).
Optimum
effect of RIP will depend on the degree of crop
cover or turf recovery, allowed by either season or management.
Prolonged and concentrated winter grazing is never helpful.
Dock
clearances (in grasses)
We
have started dock clearances in Feb/March, leaving ‘follow-up’
until May (see recent Monitored Trial 2004), but have also
cleared sites using the week before Christmas (see Stanton
Park 2000). Being stock farmers, we prefer to clear docks
while strip-grazing grasses in the winter (with lambs).
These conditions make it easy to see plants, and give us
a limited area to clear each day. On the other hand, many
long-grass sites have been successfully cleared, despite
the difficulty of locating plants. These old sites always
offer the best cover for long term control of seedlings
& re-growth, although (warning!), they also produce
multitudes of hidden plants, competing for light among the
older clusters. When conditions are reasonable, each tool
operator should lift between 80 & 90 plants per hour
(600 per day).
Example
1) Dock clearance at Stanton Park. Dec 2000.
Community
Forest Park / old grasses / wildflowers / herbs / limestone
brash,
It
took four men and a boy, one long week to clear this 7 hectare
site, finishing on Christmas eve. When we left, the outcome
was by no means certain. The land had been brown with large
infestations of mature dock, some of which stood five foot
tall. Removing those massive root clusters from the stony
ground often took our full strength, and we were both fearful
of the seed being scattered and of too many roots being
broken. While working, we were encouraged to find a white
grub enjoying destructive burrowing & eating in some
of the dock roots. After the clearance, there was no ‘follow-up’,
and the rangers in charge were slow to clear the piles of
brown plants. In the spring, the land was very lightly grazed
by sheep, leaving plenty of long grasses (and cover). Normally,
most weed control measures require ‘follow-up treatment’,
especially after major clearances.
Result:
An inspection in 2002, found very few dock plants (less
than 10 observed) growing in the cleared area. An inspection
in summer 2004, found enough visible docks to occupy two
men with L-Ds for a day. Given the extent of the original
infestation, we should count this as a remarkable success.
Remember, there was consistently good crop cover. Remember
also, the little white grub which was forced to concentrate
on the reduced rations of re-growth and root-ends, left
by the clearance. (Length 1.5 cms. Who was he ?)
Example
2) MONITORED REPORT on docks at Spaunton 2004
Removing
Spear thistle
Seedling
rosettes will appear in either March/April or Sept/Oct,
and these are the best times to remove them.
Seeds can arrive on the wind or be revealed in the seed
bank, and are encouraged to grow by extended summer or winter
grazing (esp. sheep). In an April trial on our farm, we
took 8016 seedling plants from 12 acres at a cost
of £130 (paying £6.50p per hour). A few ragwort rosettes
were also removed in the same operation, which only cost
£10-£12 per acre. Windblown seed, travelling 70 metres in
September was the known source of this particular problem,
with enforced winter grazing completing the job.
Clearances
of old and badly affected pastures, usually need
several visits, because spear thistle seeds will hide under
2nd year plate-sized rosettes and be exposed
by their removal. Second year plants also develop long,
forked roots, each of which is capable of flowering and
therefore have to be completely extracted. This is not nearly
as quick or easy as removing seedlings. Remembering the
prevailing wind direction, and that this plant spreads from
fence-lines /walls/hedges, is important.
Example
1) Spear thistle control trial at High Cross. Spaunton,
N.Yorks, 2002
Example
2) Spear thistle control contract at High Farm, Menthorpe,
NorthYorkshire, 2003. On this farm, the use of chemical
spot treatment is an option. Parts of the farm are in Countryside
Stewardship.
In
the Spring of 2002, fourteen acres were put down to a grass
/ wildflower mixture.
This
was lightly grazed or topped as it became established. By
Spring 2003, Spear thistle (lots), Common & Curled
dock (bad in areas) & Ragwort (enough),
had established themselves. In April, the L-D workforce
was asked to remove them, and four men completed the job
in just one day. A clean crop of horse hay was harvested
in late July. The cost of removing four species in one pass
was £240 or £17 per acre, and therefore much less
than spot treatment (with different chemicals etc).
Example
3) Spear & Marsh thistle control (Malham
& Ingleborough 2003-4).
Multitudes
of Marsh thistle rosettes were removed in late April for
EN at Ingleborough, and Spear thistle was selected for control
over 120 acres at Malham in 2003 for NT. Both these demonstrations
were useful, and showed officers what could be achieved,
with individual workers being paid £60 per 8hr day. (photos
available)
Pulling
Ragwort. (Common & Hoary)
Both
1st & 2nd year ragwort growth
should be visible in long grasses by mid May,
and
this is the time to start single-pass clearances.
In early June 2004, two 6 ton trailers were filled with
rosette sized plants from 60 acres of Farthing Down (Surrey).
It took two weeks for an inexperienced workforce of five,
to remove practically all plants due to flower in July (both
the early Common & later Hoary), and a large percentage
of plants comprising next years crop (2005). If the grazing
cattle numbers remain similar, next years ragwort work should
have been reduced considerably.
On
many sites, rosettes can also be very usefully removed in
the Autumn,
It
is well known, that permanently & tightly grazed pastures,
are an invitation for ragwort to succeed. Deer, sheep &
horses are the worst offenders, and their presence needs
to be fiercely controlled during winter, if turf
depth & crop cover are to be restored after rosette
clearances. In areas fenced after ragwort clearances, recovery
is always minimal compared to surrounding grazed areas.
[P.S. the shorter & lighter L-D ragwort tool is an essential
asset for large areas]
Chiselling
Creeping Thistle
We
chisel this plant in April/May, and cut the 6"rosettes
just below the point of leaf formation. In order to replace
these shoots and continue maximum photosynthesis, the plant
has to grow new shoots from its rhizome. Unfortunately,
throughout May & June, there are many potential rosettes
hiding just below the surface. These are part of the plants
normal programme of shoot emergence, throughout the season.
Completely new re-growth from the rhizome (caused by repeated
chiselling), is recognizable by being softer and less prickly.
We do use the topper on some of the re-growth on pastureland,
but in many areas on our farm, the plant is being exhausted
by chiselling. We have found that rosettes that emerge after
a chiselling in late May, hardly ever reach full maturity.
The
plant thrives on moisture and produces phenomenal growth
in a wet season. This does require repeated cutting or chiselling,
and control is noticeably easier in drier areas (banksides
in particular). Long grass can create a hindrance to chiselling,
and frustrate the ‘normal’ work-rate of 30 plants
per minute. The plant will also emerge earlier on these
ungrazed sites, where it is protected from the cold winds
of spring. As stock farmers, we try to chisel our pastures
immediately after moving the sheep, because the short grass
makes for much easier and more satisfactory work.
In
the spring of 2004, a group of 15 Hertfordshire volunteers
formed a 30 metre wide line across a grassland field, containing
Creeping thistle beds. The team were spaced two metres apart
and each carried a chisel hoe, which they used to take out
plants as the line moved forward. In an hour, ten acres
had been covered. This exercise provides a great example
of what can be achieved both selectively and efficiently,
when numerous workers using hand tools are well organized.
Mercifully, we know of no machine able to stretch 30 metres
across the land…..
[Carborundum
sticks for keeping the blade sharp, are always carried with
chisel hoes, especially in long grass]
