Control of Ragwort, Thistles and Other Problem Plants
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06 Kent Wildlife Trust Land Management Advice Series Control of ragwort, thistles and other problem plants Generally speaking, the more reptiles and nesting habitat for birds. By biodiversity there is on a site, the better. using chemical control methods, you run the This advice sheet contains However, there are undoubtedly some risk of destroying other non-invasive species information about the following species which can become invasive which are from the same family. Ragwort topics: if left unchecked. This advice sheet and thistles are both part of the Asteraceae ● conservation benefits of ‘weeds’ explains the conservation benefits (Daisy) family and no selective herbicide of injurious weed species and other will exclusively target these few species ● weeds and the law species such as bramble and nettles; and leave all the other species of thistle, ● how to prevent weeds from taking the legislation surrounding injurious mayweed, fleabane, knapweed, hawkweed hold in the first place weed species; some steps you can and daisy unharmed. ● control of ragwort, docks and take to prevent them from becoming nettles, thistles, sycamore, bramble a problem in the first place; and some Weeds and the law and dogwood, snowberry, rushes, methods of control. There is no such thing as a ‘notifiable’ weed and it is not illegal to have plants bracken Conservation benefits of such as creeping thistle growing on your ● a note on the benefits of ivy land. However, five species are classified these species ● as injurious weeds under the Weeds Act using herbicides on your site It is important to remember that these 1959: common ragwort (Senecio jacobaea), ● ‘weed’ species have evolved over millions of references and further reading creeping thistle (Cirsium arvense), spear years and play a part in the lifecycle of many ● further advice thistle (Cirsium vulgare), curled dock (Rumex animals. Common ragwort is the sole food crispus) and broad-leaved dock (Rumex plant of the cinnabar caterpillar; creeping and obtusifolius). These five species must not spear thistles provide seeds for farmland be allowed to spread to neighbouring land, birds such as linnets and goldfinches, as well especially land being used as pasture or as thistledown with which to line their nests. to produce hay or silage, and enforcement Thistles also provide nectar for bumblebees notices can be issued by Natural England on and butterflies and many invertebrates behalf of DEFRA. overwinter in their stems. Nettles are the food plant of many species including the Prevention is better comma butterfly and the burnished brass than cure moth. Bramble provides berries and nectar For many of these plants, disturbed for species such as dormouse, shelter for ground is an ideal place to germinate. It is therefore essential to avoid creating these soil conditions in the first place by ensuring that you do not overgraze your land or allow livestock to churn it up in wet weather. A closed sward (very few patches of bare ground visible) leaves little space for weed species to germinate. Please refer to our leaflets about the management of pasture Ragwort – the larval foodplant of the Comma butterfly © I. Rickards and species-rich grasslands for suggestions cinnabar moth © Kent Wildlife Trust on how to maintain a closed sward. Large print version available by calling 01622 662012 Your living landscape. Your living seas. Common fleabane © Kent Wildlife Trust Musk thistle © J.Shorter Stemless thistle © J.Shorter Carline thistle © J.Shorter Ragwort disturbed ground left after pulling can also is appropriate for the site, raise water create ideal places for dormant seeds to levels slightly as thistles don’t tend to be a Ragwort is poisonous to livestock and germinate. problem on wet grassland. to horses in particular. The toxins act cumulatively, so the more an animal eats ● cutting: this must be done before the plant Control spear thistle by digging them (potentially over several years), the more has flowered and set seed. Only do this as out or destroying the rosette when the likely it is eventually to die. The toxins are a last resort since it doesn’t kill the plant, plants are young and the soil is damp. not destroyed by cutting, spraying, pulling, can turn it from a biennial into a perennial This method is not effective with creeping digging up or drying and the seed can remain and can cause it to ‘coppice’ and flower thistle since it tends to propagate through dormant for up to 20 years, which is why it later in the season. Do not put livestock on its roots rather than its seeds: fragments may sometimes come up in even the most site for at least six weeks. of root (rhizome) left in the soil after well managed pasture and why it is essential pulling/digging can remain dormant for ● herbicide application: if the area to be not to leave cut, treated or wilted ragwort in a years and are very efficient at regenerating treated is fairly small, try spot-treating field which may be accessed by livestock. into a new plant. with a knapsack sprayer as this is very Control by: target specific. Blanket spraying with a Control creeping thistle by cutting before ● pulling or digging up: can be done by tractor-mounted sprayer can be used for the flower bud turns purple and removing hand over smaller areas or with a tractor- serious infestations but will destroy many the plants to avoid any chance of the seed mounted mechanical puller over larger surrounding plants and other wildlife. ripening. At this time, the plant has put all areas. Gloves need to be worn since the Alternatively, if the ragwort is very tall and its resources into the buds and is more poison can irritate human skin. The best stands above other vegetation, then use a readily weakened by any cutting. Use a time to do this is when the plants are still hand held or tractor-mounted weed-wipe. strimmer, scythe, or tractor-mounted cutter young and the soil is soft following rainfall for larger areas. As a last resort, apply a To dispose of ragwort, stockpile it in one (tools such as ‘lazy dogs’ can be very useful herbicide in May or June (see section on area, on a site that will not be accessible to for this task – see Further reading section). ragwort). livestock either now or in the future, and let Ragwort can regenerate from fragments of it rot down. Alternatively, you can burn it, root left behind after pulling. The areas of although this tends to be impractical since the ragwort will be green and therefore does Leaf of common ragwort © N. Jennings not burn easily. Docks and nettles Follow the guidelines for good sward management to prevent docks and nettles growing in the first place. Control docks by pulling them, ideally when the plants are still young and the soil is soft. Control nettles Spear thistle © G.Christian by cutting repeatedly since this will weaken them. If you need to use a herbicide, then try to use a selective one. Thistles Follow the guidelines for good sward management to prevent thistles from growing and spreading. If you are able to, and this Snipe © Amy Lewis Bumblebee on thistle © Les Binns Treecreeper © Amy Lewis Sycamore Rushes can be quite invasive; they also provide little nutritional value to livestock Sycamore provides quality timber, coppices and are unpalatable, so animals will only well, and can support large numbers of eat them if there is nothing else left. As a invertebrates. However, strictly speaking, it result, farmers and graziers will generally is not a native species. It can outcompete control rushes by topping them or applying native species and will keep seeding into herbicides. From a conservation perspective, fields where it is growing adjacent to the least damaging way to control them is grassland. It also goes into leaf earlier in by grazing, ideally with breeds such as Konic the year, shading out flowering woodland horses, which can handle most vegetation. plants, and its leaves rot down more slowly Dogwood © Philip Precey Top the rushes in spring to make the regrowth than in other species. For these reasons, it a little more palatable and then graze. is best kept away from ancient woodlands some on your land. These species can be Alternatively, top them in the autumn and and you may also wish to control any controlled by spring grazing. Bramble can also graze – although there will be no regrowth, sycamores that are encroaching on be cut on rotation, ensuring there is always some left for wildlife. livestock may trample the hearts of the grassland sites: clumps and cause enough damage to limit ● clear the larger sycamore trees in Snowberry further growth. autumn-winter and stump treat with Snowberry is an introduced species and herbicide the day they are felled. Check can be very invasive. The best way to avoid with the Forestry Commission before it encroaching on your grassland is to do doing any felling work to find out if you some spring grazing (April, May), since the need a felling licence. shrubs will be young and the new growth will be more palatable to livestock. You could ● clear smaller sycamores by hand with try topping it regularly (cutting off the top loppers or a bow-saw, during the winter growth) to prevent it from getting too woody; months, and stump treat immediately, topping it will also prevent it from seeding and since the herbicide won’t be absorbed producing berries, which birds then like to eat, Rushes © Kent Wildlife Trust when the sap is rising; alternatively, thus dispersing the seed nearby in your fields. spray the leaves in spring (when the leaves are freshly emerged) or in the Rushes Bracken autumn From a conservation point of view, rushes Bracken can take over a site if left unchecked.