As far as I am concerned there are no such thing as weeds, they are all wildflowers, but humans like to give things that they don't like, or perceive as a problem, a derogatory name, a name that sums up why something should not be tolerated, liked, or even accepted. But weeds are wildflowers, and they are some of the best wildflowers as far as pollinating insects are concerned. And I have used 'weeds' as my blog title just to be a bit provocative, because I absolutely love 'weeds'!
As Marillion said, on the song Beautiful, from their stonking album Afraid Of Sunlight:
Everybody knows we live in a world where they give bad names to beautiful things
Everybody knows we live in a world where we don't give beautiful things a second glance
Heaven only knows we live in a world where what we call beautiful is just something on sale
People laughing behind their hands as the fragile and the sensitive are given no chance
We don't have to live in a world where we give bad names to beautiful things
We should live in a beautiful world
We should give beautiful a second chance
Now, Marillion weren't talking about 'weeds' in their song, but they could have been, as I think the lyrics fit what a lot of people think about these gorgeous wildflowers.
If you haven't heard Beautiful, by Marillion, you can listen to it by clicking HERE
One of my clients recently asked me to provide him with some information on the conservation value of some common 'weed' species, and these were Ragwort, Nettles, Thistles, Docks and Rushes. He was interested to know whether they needed controlling on his farm, and if so where, and by how much. However, to put this into context, on his farm the farming is secondary to, and is there to support the biodiversity on the farm, so in asking me the question he was erring on little or no control, depending on the situation. I carried out a bit of a literature review, and looked at as much information that I could find on the conservation value of these plant species, and learnt a little too.
Anyway, it was an interesting piece of work, and I have replicated some of it here in my blog, in relation to some of the insects that I have recorded of late, just to illustrate how important these common wildflower species are to pollinators, and to some see-eating bird species as well.
Throughout this piece, I will intersperse it with pictures of a variety of species, all utilising these common wildflower species.
Ragwort
There are 35 insect species that totally rely on Ragwort for food, including seven species of moth (particularly important for Cinnabar Moths) and seven beetle species. Another 83 species are recorded as using Ragwort, and often it forms a significant food source. There are then a further estimated 50 species of parasite, in turn, feeding on those insects.
On top of those 133 species, Ragwort is a significant source of nectar for other insects, including bee species that specialise in feeding on daisies, and many species of butterfly. Government research shows that of over 7,000 plant species in Britain, Ragwort is the 7th most important nectar-producing plant.
On top of those 133 species, Ragwort is a significant source of nectar for other insects, including bee species that specialise in feeding on daisies, and many species of butterfly. Government research shows that of over 7,000 plant species in Britain, Ragwort is the 7th most important nectar-producing plant.
Cinnabar Moth caterpillars on Ragwort
A new study by researchers at the University of Sussex, has demonstrated that weeds are far more valuable in supporting biodiversity than we give them credit for. This study compared the biodiversity value of plants classified as ‘injurious weeds,' with those stipulated by the Department for Environment, Food and Rural Affairs (DEFRA) for pollinator targeted agri-environmental options, such as Red Clover and Wild Marjoram.
Their findings show that the abundance and diversity of pollinators visiting weed species are far higher than DEFRA recommended plants. Ragwort has open flowers, that allow access to a wide variety of pollinator species, and they produce, on average, four times more nectar sugar than the DEFRA recommended plant species.
Their findings show that the abundance and diversity of pollinators visiting weed species are far higher than DEFRA recommended plants. Ragwort has open flowers, that allow access to a wide variety of pollinator species, and they produce, on average, four times more nectar sugar than the DEFRA recommended plant species.
Common Drone Fly on Ragwort
Research shows that Ragwort is toxic to animals. However, what is clear from scientific research, is that actual poisoning is a rare event.
Ragwort contains compounds that are poisonous to most vertebrates. These are pyrrolizidine alkaloids, and these substances occur in other plants as well. In fact, they occur in 3% of the world's flora.
The question is how much needs to be consumed for an animal to be poisoned. It has been found that it lies between 5 % and 25% of body weight for horses and cattle.
Quite often, you will hear people saying that there are automatic legal obligations to treat and remove Ragwort from land, but in fact there are not. It is simply the case that there is nothing in the legislation that says that you automatically must eliminate ragwort from land.
Ragwort is mentioned in the Weeds Act 1959, and the Act says:
Ragwort contains compounds that are poisonous to most vertebrates. These are pyrrolizidine alkaloids, and these substances occur in other plants as well. In fact, they occur in 3% of the world's flora.
The question is how much needs to be consumed for an animal to be poisoned. It has been found that it lies between 5 % and 25% of body weight for horses and cattle.
Quite often, you will hear people saying that there are automatic legal obligations to treat and remove Ragwort from land, but in fact there are not. It is simply the case that there is nothing in the legislation that says that you automatically must eliminate ragwort from land.
Ragwort is mentioned in the Weeds Act 1959, and the Act says:
Where the minister of Agriculture fish and food (in this act referred to as ' the Minister') is satisfied that there are injurious weeds to which this act applies growing upon any land he may serve upon the occupier of the land a notice, to take such action as may be necessary to prevent the weeds from spreading.
This legislation does not force landowners to control Ragwort, nor does it place an obligation on them to do so.
The Weeds Act has been subsequently amended by the Ragwort Control Act, which only provides guidance for the creation of a code of practice.
Code of practice: Ragwort:
1. The Minister may make a code of practice for the purpose of providing guidance on how to
This legislation does not force landowners to control Ragwort, nor does it place an obligation on them to do so.
The Weeds Act has been subsequently amended by the Ragwort Control Act, which only provides guidance for the creation of a code of practice.
Code of practice: Ragwort:
1. The Minister may make a code of practice for the purpose of providing guidance on how to
prevent the spread of Ragwort.
2. Before making the code, the Minister must consult such persons as he considers appropriate.
3. The Minister must lay a copy of the code before Parliament.
4. The Minister may revise the code; and subsections (2) and (3) apply to the revised code.
5. The code is to be admissible in evidence.
6. If the code appears to a court to be relevant to any question arising in proceedings it is to be taken
2. Before making the code, the Minister must consult such persons as he considers appropriate.
3. The Minister must lay a copy of the code before Parliament.
4. The Minister may revise the code; and subsections (2) and (3) apply to the revised code.
5. The code is to be admissible in evidence.
6. If the code appears to a court to be relevant to any question arising in proceedings it is to be taken
into account in determining that question.
Ragwort is not a notifiable weed that must be reported to someone in authority. The above is the only piece of legislation that can place an obligation on anyone, and it does not say that it is notifiable. There is no requirement in law to notify, inform, or tell anyone of the occurrence of Ragwort anywhere.
Ragwort is not a notifiable weed that must be reported to someone in authority. The above is the only piece of legislation that can place an obligation on anyone, and it does not say that it is notifiable. There is no requirement in law to notify, inform, or tell anyone of the occurrence of Ragwort anywhere.
Painted Lady on Ragwort
Ragwort seeds are wind-blown, and many people therefore assume that the seeds readily colonise new sites. This is not the case. Research has shown that it is not a common event.
Several studies have been carried out into Ragwort seed dispersal. One study found that 60% of the total seeds produced were deposited at the base of the plant, and at 36 metres from the plant there were virtually no seeds deposited at all.
Another study showed that, when tested in a variety of conditions, 31% of the seeds travelled only 1 metre, 89% of them 5 metres or less, and none were collected more than 14 metres from the source.
It is important to remember when talking about seed dispersal, that the conditions for the seed when it lands is a consideration. It is also important to remember that a plant will on average only produce one offspring.
One of the problems is that if Ragwort is pulled up out of the ground, small pieces of roots remain, and these roots can then regrow into new plants.
The number of seeds produced by a Ragwort plant is often stated as being 150,000, and this is then built up to make out that this makes the plant a risk for spreading everywhere.
This figure is at the top end of the plant's production, and many plants produce far less than this. The range of seeds produced per plant from two studies gives 4,760 – 117,740 seeds per plant over eight sites, and 7,070 – 20,150 seeds per plant over six sites. An average of 15,897 – 33,095 seeds per plant.
There is sometimes a conflict between the need to manage Ragwort and its value to wildlife. It is important to take a balanced view as to whether there is a need to control Ragwort, and decide on any action case-by-case. Ragwort poses the greatest risk to livestock when cut and dried, either in hay, or as arisings from topping. The use of chemical sprays can also make it more palatable in its living form. Where Ragwort is considered to present a risk to livestock, e.g., within a grazing area or hay field, some management might be needed.
On this farm, Ragwort is mainly found alongside some tracks, and in the stoned areas surrounding the ponds, areas where they pose no risk. Ensuring livestock numbers are appropriate, and careful timing of grazing can help prevent Ragwort becoming problematic.
You won't be surprised to learn, that my recommendation was that no control of Ragwort should be carried out, due to their high conservation value, unless it is considered it presents a risk to livestock.
You won't be surprised to learn, that my recommendation was that no control of Ragwort should be carried out, due to their high conservation value, unless it is considered it presents a risk to livestock.
Nettles
As you know, Nettles are a very common plant, and its preference for damp, fertile and disturbed ground makes it a good coloniser of places enriched by human activities, such as agriculture.
However, Nettles are great for wildlife, and the caterpillars of the Small Tortoiseshell, Comma, Red Admiral, and Peacock butterflies use them as foodplants. Young Nettles are the food plant of many moth larvae, such as the Snout, Dot, Burnished Brass and Mother of Pearl. Ladybirds feed on the aphids that are found on them, providing an important food source for the Ladybirds. Seed-eating birds feed on them when they set-seed in the autumn. They also support over 40 other insect species.
However, Nettles are great for wildlife, and the caterpillars of the Small Tortoiseshell, Comma, Red Admiral, and Peacock butterflies use them as foodplants. Young Nettles are the food plant of many moth larvae, such as the Snout, Dot, Burnished Brass and Mother of Pearl. Ladybirds feed on the aphids that are found on them, providing an important food source for the Ladybirds. Seed-eating birds feed on them when they set-seed in the autumn. They also support over 40 other insect species.
Red Admiral on Nettles
As stated above, Nettles are important habitats for a great range of invertebrates but in large numbers, can threaten important aspects of a grassland habitat and require careful management.
Like the Dock, the spread of Nettles normally occurs on bare ground or gappy swards created through overgrazing or poaching, especially in shady areas, around feeding sites and in enriched sites such as dunging areas. Weed seeds can be brought in with supplementary feed and in dung from elsewhere.
At my client's farm, it is unlikely that Nettles are, or will become an issue. Less grazing, no applications of slurry, and the future use of composted material will ensure that favourable conditions for Nettles within the meadows and grazed pastures will diminish. So, my recommendation was that no control of Nettles should be carried out due to their high conservation value, and where they do occur, they should be retained because of this.
Thistles
Thistles are very important plants for some seed-eating birds, and as a pollen and nectar source for a range of insects. The Goldfinch is the bird most associated with thistles, the seeds of which make up one third of its diet. Within the same family are Greenfinch, Siskin, Linnet, Twite, and Redpoll, which eat thistle seeds, and use thistledown in the nest.
Butterflies, including Painted Lady larvae feed on the leaves. Other butterflies such as the White Letter Hairstreak, Peacock, and Meadow Brown use thistles as a nectar source.
Butterflies, including Painted Lady larvae feed on the leaves. Other butterflies such as the White Letter Hairstreak, Peacock, and Meadow Brown use thistles as a nectar source.
Peacock on thistle
Other invertebrates including bees feed on nectar, and use the micro-habitats in and on thistles. The flower head provides the greatest diversity of insects, and the stem is particularly important as an over-wintering habitat.
Buff-tailed Bumblebee on thistle
However, in some grassland situations, Creeping Thistle, and Spear Thistle in particular, can become a problem. Other thistles may be rare, valuable to wildlife and unlikely to cause problems.
It is a case of knowing which species of thistle that you have, and then deciding whether it is a problem or not.
A Creeping Thistle problem should not develop in a dense, well-managed sward of perennial grasses, but when it does occur, it can be very invasive. It only rarely propagates itself by seed, as the fluffy fruit heads often have no fertile fruits. Instead, its root propagation is very efficient, and fragments of rhizome can remain dormant in the soil for years and then appear when there is a gap in the sward. A small cutting can spread into a 20 m patch in just two years.
It is a case of knowing which species of thistle that you have, and then deciding whether it is a problem or not.
A Creeping Thistle problem should not develop in a dense, well-managed sward of perennial grasses, but when it does occur, it can be very invasive. It only rarely propagates itself by seed, as the fluffy fruit heads often have no fertile fruits. Instead, its root propagation is very efficient, and fragments of rhizome can remain dormant in the soil for years and then appear when there is a gap in the sward. A small cutting can spread into a 20 m patch in just two years.
For all these wildflower species, I am not calling them weeds anymore, I detailed the control options available to my client where necessary, but I'm not going to bore you with these practical management details here.
My advice to my client regarding Thistles, was to only consider controlling them in meadows where there are large numbers.
My advice to my client regarding Thistles, was to only consider controlling them in meadows where there are large numbers.
Docks
Docks are an important plant for a range of insects, such as capsids (type of bug), weevils, beetles, spiders, and many others. But in large numbers, can threaten important aspects of a grassland habitat e.g., species rich meadows, and require careful management.
The spread of docks normally occurs on bare ground or gappy grassland swards created through over-grazing, or livestock poaching (where livestock leave hoofmarks creating extensive areas of bare ground), especially in shady areas and around feeding sites, and in enriched areas, such as dunging areas. Weeds can be brought in with supplementary feed and in dung from elsewhere.
My advice was to control Docks in both pastures and meadows, where there are large numbers. It is important to control them in species rich meadows, or any meadows where restoration is being considered.
Docks are an important plant for a range of insects, such as capsids (type of bug), weevils, beetles, spiders, and many others. But in large numbers, can threaten important aspects of a grassland habitat e.g., species rich meadows, and require careful management.
The spread of docks normally occurs on bare ground or gappy grassland swards created through over-grazing, or livestock poaching (where livestock leave hoofmarks creating extensive areas of bare ground), especially in shady areas and around feeding sites, and in enriched areas, such as dunging areas. Weeds can be brought in with supplementary feed and in dung from elsewhere.
My advice was to control Docks in both pastures and meadows, where there are large numbers. It is important to control them in species rich meadows, or any meadows where restoration is being considered.
Rushes
Low levels of rush cover are beneficial to breeding birds, as the tussocks provide cover for nesting and for concealing chicks, but heavy infestations have an adverse impact on the value of grazing pasture.
Management should be considered when infestations cover more than one-third of a field's area, as its value to breeding waders is reduced.
Different wader species select fields with different sward heights. Lapwings select fields with a short sward and scattered tussocks, which will conceal their nests and chicks, but while leaving their all-round view uninhibited.
At the other extreme, Snipe prefers a higher level of concealment in taller vegetation. So, a wide variety of sward heights is beneficial. Rushes can provide tussocks which are useful for cover, but if they create dense cover then the field will lack the shorter areas that are useful for feeding.
If rushes take up more than one-third of a fields area, then grazing management, which is essential to maintaining the grassland for breeding waders, is made more difficult.
At my clients' farm we have a successful track record of managing rushes by topping and aftermath grazing with cattle and sheep. So, I recommended that in any pastures where rush cover is approaching one third of a field’s area, then the rushes should be managed by this method.
Management should be considered when infestations cover more than one-third of a field's area, as its value to breeding waders is reduced.
Different wader species select fields with different sward heights. Lapwings select fields with a short sward and scattered tussocks, which will conceal their nests and chicks, but while leaving their all-round view uninhibited.
At the other extreme, Snipe prefers a higher level of concealment in taller vegetation. So, a wide variety of sward heights is beneficial. Rushes can provide tussocks which are useful for cover, but if they create dense cover then the field will lack the shorter areas that are useful for feeding.
If rushes take up more than one-third of a fields area, then grazing management, which is essential to maintaining the grassland for breeding waders, is made more difficult.
At my clients' farm we have a successful track record of managing rushes by topping and aftermath grazing with cattle and sheep. So, I recommended that in any pastures where rush cover is approaching one third of a field’s area, then the rushes should be managed by this method.
From the above, I hope you can see how important these common wildflower species are, and just to let you know my client decided to follow my advice with a few inputs from his own experience.
I can't believe that the month of July has nearly disappeared, with us only managing to complete one ringing session at the Nature Park. July is probably the joint best month of the year, particularly for warblers, so to only have completed one visit is a huge disappointment. Let's hope that August is better!
Before the rain came in on Friday, Gail and I had a walk along the Quay at mid-day. We left it until mid-day as it was quite a cool, blustery day, in the hope of a few insects, and the cooler weather (virtually full cloud cover) certainly negatively impacted our butterfly count. We counted six Small Whites, a Gatekeeper, a Common Blue, two Meadow Browns, a Holly Blue, a Red Admiral and two Peacocks. We also had a several Cinnabar Moth caterpillars on some weeds , sorry Ragwort, and there were numbers of bees and hoverflies on all the common wildflowers.
Out on the mud was a single Black-tailed Godwit, four Oystercatchers and 22 Redshanks. Roosting/loafing Gull numbers had dropped to ten Lesser Black-backed Gulls, three Black-headed Gulls and 45 Herring Gulls.
Two Little Egrets fed along the edge of the river, and we had our first juvenile Shelducks roosting out on the mud at the edge of the saltmarsh; two adults and five juveniles. Two Swifts were worth entering in my notebook, and that was about it.
And still, it rains!
2 comments:
An interesting read Seamus, I'll keep some of that in mind...
Thanks Stewart.
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