Broad-leaved dock and curled dock are two of the most widespread docks in the UK. Eighteen other species of Rumex commonly referred to as ‘dock’ are found growing in our countryside; some are UK natives, and some have been introduced. Hybridisation between species frequently occurs, so identification can be challenging. However, for control purposes, distinguishing between different species and hybrids isn’t essential, as they can all be controlled with the same methods.

The descriptions and images below will help you identify broad-leaved and curled docks. RHS members can use the RHS Gardening Advice service for help identifying other species.

Broad-leaved dock (R. obtusifolius) is a robust, long-lived perennial. Its large, oval-shaped leaves have slightly wavy edges and grow to about 30cm (12in) long and 15cm (6in) wide. Low

Rosettes are the circular arrangement of flower petals; or a cluster of leaves radiating from approximately the same point usually around a stem. Examples include aeonium and most succulent plants, African violets, primula, sempervivums.

These docks are UK native wildflowers and valuable wildlife plants, providing food for many insects and birds. The Biological Records Centre lists over 80 insects that use broad-leaved dock as a food plant; these include the small copper butterfly, and garden tiger and clouded buff moths. Dock leaves are a main food source for the larvae of green dock beetles and the seeds are important winter food for birds such as dunnocks and house sparrows.

It is perfectly acceptable, and indeed very beneficial, to allow docks to grow in some parts of your garden. However, where docks compete with other plants for moisture, nutrients, space and light, you might choose to remove them or limit their spread.

Docks are useful plants, with a long history of medicinal use. Their leaves, roots and seeds have been used to treat a wide range of ailments and it is widely believed that rubbing a dock leaf on a nettle sting helps to ease the discomfort. They also make an attractive addition to perennial meadows, with their reddish-brown seed heads providing interest well into the winter.

Despite their many benefits, broad-leaved and curled docks are both listed in the Weeds Act 1959, which exists to control the spread of plants considered problematic on agricultural land. Under the legislation, control measures to prevent broad-leaved and curled docks from spreading need to be taken if an order to do so is served to you by a government official.

Although their inclusion in the Weeds Act 1959 reflects how successful docks are at spreading, they are much easier to manage in a garden situation compared to large areas of agricultural land.

Here are our answers to your most common questions about dealing with docks:

How invasive are docks?

Docks spread easily by seed and individual plants can produce large numbers of seed that remain viable for many years. The seed is dispersed by wind, water and animals, and can be introduced into gardens or allotments in manure. The good news is that deadheading  plants prevents self-seeding and limits spread.

Seedlings often emerge in spring or early autumn. Young plants quickly develop a taproot and can regenerate from sections of root, so may be spread unintentionally by gardeners composting roots or chopping them up when digging. However, sections of root deeper than about 12cm (5in) are much less likely to regrow.

Although they prefer fertile, cultivated ground and grassland, docks can grow in a wide range of soils and conditions, and once established, they can cope with heavy competition from other plants.

Do I need to get rid of docks?

In most gardens it is not necessary to completely eradicate docks. Allowing some to grow in a species-rich lawn, meadow or wildlife corner is a great way to boost the biodiversity of your garden and gives you the chance to enjoy their attractive flowers.

It is, however, a good idea to control docks to stop them spreading to parts of your garden where they might smother and outcompete other plants.

In the unlikely event that you are served with an order under the Weeds Act 1959 to control broad-leaved and/or curled dock on your land, then you must comply with this.

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Flower spikes of curled docks provide vertical accents in perennial meadows  

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Rusty coloured upright stems persist through autumn and sometimes into winter    

What is the easiest way to kill docks?

If you have docks growing where they are not wanted, there are several ways to control them:   

• Deadhead – remove faded flowers in summer to prevent self-seeding.  
• Hoe off seedlings – do this promptly, when plants are still very young, before they develop taproots. Hoe on a warm, dry or windy day when possible, so exposed roots dry out quickly and die. 
• Dig or fork out plants – ideally do this when plants are still young and haven’t had time to develop a deep root system or set seed. Aim to remove the top 12-15 cm (5-6in) of the root system; sections of root deeper than this are unlikely to regenerate. With awkwardly positioned plants, initially remove as much root as you can and then remove regrowth when it appears – over time this will weaken the plant.  
• Cut regularly – use a strimmer, brushcutter or mower for large areas. Cutting back new growth regularly will weaken and eventually kill docks. This is likely to take several years but is better for soil health as it limits disturbance.  
• Smother seedlings – apply a mulch of organic matter, around 10cm (4in) thick, to your soil in early spring to smother emerging seedlings. Alternatively fill gaps in borders with ground cover plants.  
• Smother plants – cover with a layer of compostable material, such as cardboard, and then a layer about 20cm (8in) thick of organic matter, such as bark or wood chips. Alternatively, use a heavy grade biodegradable mulch matting. This will block light and prevent growth, causing the root system to die. Keep soil covered for a few years, topping up the mulch layer if necessary, to ensure this method is effective. As dock seed can remain viable for many years, regularly check for and control emerging seedlings when the cover is removed.  
• Avoid disturbing the soil – docks can regenerate from root fragments, so avoid digging over or rotavating the soil where they grow, as this will chop up and spread the roots. 

Should I use weedkiller?

As non-chemical control methods are effective, even if time-consuming, there is no need to use weedkillers.

For more information, see our page on non-chemical weed control.

The RHS does not support the use of weedkillers and recommends that alternative control methods are used. However, we do note that when gardeners struggle to control plants with cultural methods, regulated weedkillers/pesticides for home gardeners are available for use legally. Garden centres and large retailers selling weedkillers have trained staff who can advise on suitable products for your needs.