Two types of herbs, buttercup, and sorrel (dock), are particularly noticeable after the summer grazing season because in many regions they have remained standing with their seed-sprouting stems.
The smaller of the two is the buttercup. Buttercups (Ranunculaceae) are found almost all over the world. In Europe alone, this plant family has 60 subspecies.
Buttercup species
As a horse owner we should at least know two subspecies: the meadow buttercup and the creeping buttercup, as these are the most common in our fields.
Both the meadow buttercup and the creeping buttercup thrive in our grazing pastures. If the two are standing next to each other, then the meadow buttercup is about 1/3 taller when fully grown than its little brother, which – as its name suggests – grows rather low and ‘creeps’ across the pasture.
The meadow buttercup is less demanding in terms of soil and nutrient supply. Its leaves are strongly and distinctively serrated and resemble the claw of a cockerel. There is a clear distinction from the more rounded leaf shape of the creeping buttercup.
Ranunculus species contain the toxin protoanemonin, which can cause skin irritation. The levels in the meadow buttercup should not be underestimated, whereas they are significantly lower in the creeping buttercup.
During the drying process, e.g. after the hay harvest, the protoanemonin decomposes within six to eight weeks and thus loses its toxicity. This is why buttercups are unproblematic in hay meadows, as freshly harvested hay should be allowed to rest for 8-12 weeks before being fed.
Overall, buttercups tend to be avoided by horses on pasture, so poisoning is extremely unlikely. However, they are plants that take the place of our valuable grasses and healthy herbs.
Meadow buttercup on the left and creeping buttercup on the right
©Helmut Muss
Types of Sorrel (dock leaf)
The much bigger thieves robbing of valuable pasture space are the broad-leaved dock (Rumex obtusifolius) and the meadow sorrel (Rumex acetosa).
In general, more than 130 species of dock belong to the extensive genus of the knotweed family.
The small sorrel also belongs to this family. In contrast to its 2 siblings, sorrel can be suppressed by raising the pH value in the soil. This is why it is also considered a reliable indicator plant for soil that is too acidic. The soil coverage isn’t anywhere near as problematic as it is with the buttercup.
The leaves of meadow sorrel and broad-leaved dock deprive other plants of light. This means that there could be up to 30 grass plants in the same place as a single broad-leaved dock plant.
Added to this is the large number of seeds it throws out. It is not only the sheer number of seedlings (approx. 7000), but also the survivability of these seeds that presents us with a major problem. Officially, the germination period is given as 40 years. From experience, however, it can be assumed that activity goes beyond that.
Dock species are also often referred to as ‘arable weeds. This is because the seeds need a period of exposure to light and therefore like to germinate in arable land, as these are regularly harvested.
©Helmut Muss
What can be done against unwanted species
When the dock seeds fall to the ground, they must first be covered with soil to maintain their germination capacity. In horse grazing pastures, this is done by the horses’ hooves tramping them into the soft soil after rain. In order to actually germinate, they need to be exposed to light again, so they have to be brought to the surface once more and then covered again before germination.
This is why I also recommend avoiding tillage on pastures and meadows if at all possible. Dormant dock could be woken up as well as other herbs that require similar conditions to germinate. These include various other species of knotweed family as well as orache. The horses are taking over the job of tilling the soil naturally, and therefore insure the life cycle of the dock leaves in the pasture unknowingly.
By not allowing the horses to eat the pasture bare, the existence of the dock leaf and the buttercup will be a lot more difficult. If the lower part of the grasses, low meaning not below 10 cm are left standing less light will penetrate the soil on the ground and therefore less unwanted plants will be able to make their appearance by regularly reproducing. Evidentially dock leaves and buttercups are particularly plentiful in pastures that are always overgrazed, and poor pasture management is visible for years to come, even if the pasture has long been ceased for grazing.
Alternative measures to prevent the spread of buttercup and sorrel
Apart from chemical control, there are a few measures we can take to prevent the spread of buttercups and dock leaves.
- In order to keep the ‘tillage’ caused by the horse’s hooves to a minimum, we should avoid grazing on wet ground, as these are often literally “ploughed up” by the horses’ hooves. In addition, the denser our pasture vegetation is, the more stable the sward is and the less likely it is to be torn up when the horses have a ‘run a round”.
- Like all plants, buttercups and dock leaves also need light to grow. The denser our pasture is, the less light reaches the ground and allows unwanted seeds to germinate or young plants to flourish.
- If there are areas on a pasture that are almost completely covered by buttercups or dock leaves, it is advisable to have the mulcher work deeper, i.e. close to the ground, when mulching the grazed pasture. This reduces the ability to compete with other plants in the pasture. Dock leaves and buttercups first have to sprout again, and other plants can use this time to overgrow them and deprive them of light.
If the summer is dry, deep-rooted plants have an advantage. This is not so much the case for buttercups, as they only root about 50cm deep, whereas grass usually roots 40-45cm deep. Dock leaves, however, really come into their own in dry conditions, as its roots reach down to a depth of 3 metres.
Closing gaps in the grass sward should therefore regularly be part of the management programme in spring and early autumn in order to deprive unwanted plants of light as quickly as possible.
Repeated sowing with smaller seed quantities minimises the risk. If the summer is wet and inconsistent, we can also use the time in summer to close our pasture gaps.
Finally, a tip: If you only have a few dock leave plants in the pasture, pull them out by hand before they set to seed and remove them from the pasture. The roots will sprout again, but you will prevent around 7000 seeds from lying in the waiting for the next 40 years.
Conclusion
Buttercups and dock leaves can be kept in check with the right pasture management.
Guest author Helmut Muß from Die gute Pferdeweide (The Good Pasture for Horses)
Als Landwirtschaftsmeister hat er jahrelange Erfahrung in der Gestaltung hochwertiger und artgerechter Pferdeweiden.
In seinen Seminaren, Webinaren und Beratungsvideos teilt er sein umfangreiches Pflanzenwissen unter dem Titel "Die Gute Pferdeweide".
Seine Philosophie der Weidepflege entwickelt sich stetig weiter durch seine Reisen und den Austausch mit Pferdehaltern im deutschsprachigen Raum, immer getreu seiner Maxime: "Die Weide vom Pferd her denken".
https://www.diegutepferdeweide.de/
🇬🇧 Helmut Muß, who grew up on a farm and has a deep passion for nature, has established himself as a consultant for pasture management.
As a Master of Agriculture, he has many years of experience in designing high-quality and species-appropriate horse pastures.
In his seminars, webinars and advice videos, he shares his extensive plant knowledge under the title ‘Die Gute Pferdeweide (the good horse pasture)’.
His philosophy of pasture care is constantly evolving through his travels and exchanges with horse owners all over Germany, always true to his maxim: ‘Die Weide vom Pferd her denken (Think about pasture from the horse's perspective)’.
https://www.diegutepferdeweide.de/
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