Growing

Controlling weeds: Creeping Buttercup

Image from lawnweeds.co.uk

Creeping buttercup, Ranunculus repens, is also known as Crow’s foot and Restharrow. It is a herbaceous plant that can grow up to 50cm tall. Just under the surface the plant sends out runners, called stolons, which means it can quickly infest an area.

How can you control creeping buttercup in your vegetable beds, borders or lawn?

The leaves are quite distinctive!

Creeping buttercup likes moist soil and will grow with-in grassy areas as well as spreading via runners into your vegetable beds. The plant will also spread via seed.

How to control buttercup:
Creeping buttercup is relatively easy to dig out as it has quite shallow roots. Dig buttercups out in the spring and keep removing any plants that appear through summer and autumn. Alternatively, you can use the ‘no dig’ method to mulch the plant to exclude light. It can be quite a tough weed so be prepared to use a trowl to remove any persistent plants that do pop through. Start with a thick layer of cardboard before a good (ideally 6-8inch thick) mulch of compost or composted manure. This is the method I am currently using in our new plot 5b (add link to video). Glyphosphate weedkiller will work if you are happy to use this method. This weed is more difficult to control if it is within an established border or within grass paths. If you regularly mow the paths the plant will be kept under control. However, this really means weekly minimum in the summer.

Runners appear from the main plant in in a similar way to strawberries. These grow into additional plants if the runner is not removed or mulched well.

Image from lawnweeds.co.uk

The bright yellow flowers are pretty, but don’t be fooled. However, in spring buttercups can be an important nectar source for pollinators. If you are on an allotment ground then a wild border allowing native ‘weeds’ to grow is a way of keeping this important habitat.

Image courtesy of Phil_Bird at FreeDigitalPhotos.net

An activity many of the more mature amongst us will remember was placing this flower under our friend’s chins to see ‘if they like butter’. The outer layer of petals have very flat cells allowing them to reflect back light. They contain chemicals that absorb some of the wavelengths of light so the petals appear a particular colour. Scientists believe that the reason buttercup flowers reflect yellow light so well is that the cells found in the outer layer of the petals of the buttercup flower are actually a double layer. The small proportion of yellow light that makes it through the first layer of cells is reflected by the second layer making them exceptionally good at reflecting yellow light!

White light is made up of a number different colours (wavelengths). In buttercups. the yellow wavelength of light is reflected back off the plant by the special double layer of reflective petal cells. The other wavelengths are absorbed making for a brightly shining yellow flower