Identifying and removing weeds
Weeds are an annoying but unavoidable fact of life for gardeners. Identifying them correctly will help you tackle them early.
24.01.2025
Identifying weeds
You may have heard it said that a weed is simply a plant growing in the wrong place – and there is some truth in this: no strict definition of what a weed is exists, and many of the plants we refer to as weeds serve as valuable wild herbs or indicator plants in other contexts. So identifying the plants correctly is worthwhile, in case you uncover a surprising benefit from your outdoor interloper.
For home gardeners, the term “weeds” describes unwanted plants that grow in the garden or the lawn. They are wild plants which are generally extremely resilient and propagate rapidly. The most familiar weeds can also withstand extremes of hot or cold weather very well, which is why it often seems nigh-on impossible to entirely kill them off. Many weeds will deposit seeds, runners and stolons that remain dormant, deep in the earth, only to germinate readily – even decades later – when brought closer to the surface by digging.
Weeds grow in one of two ways: they spread either by their roots or their seed. Identifying the type of weed you have means you can find out how it propagates, and therefore how best to eliminate it. There are two types of weeds: root weeds and seed weeds. They differ in their main mode of reproduction and control.
Root-propagated weeds
The hardy roots of these weeds can spread out across the bed or under the grass. Footpaths and even fencing don’t stop them: their root rhizomes are sometimes many metres long, and can meander through the entire garden.
When identifying weeds, it is important to establish the root-spreading types and tackle them appropriately. Shredding or mowing these weeds into small pieces does nothing to destroy them, and is in fact likely to compound your problem by creating many more starting points from which plants can grow. The only way to get rid of these weeds once and for all is to carefully dig them out of the earth with their roots – ideally all in one piece. This kind of weeding is laborious, but it pays dividends into the future.
Seed-propagated weeds
This type of weed produces large quantities of seed, meaning it can reproduce quickly and on a wide scale. Dandelions are a classic example of a troublesome weed that spreads in this way, when the flower matures to become a “dandelion clock” and efficiently distributes its distinctive wind-borne seeds.
Other common seed-producing weeds include gallant soldiers, chickweed and greater celandine. These mostly annual plants can reproduce across large distances, and the genetic material can survive for years or even decades in soil, before germinating again when the ground is dug over. That is why weeds often spring up in freshly created beds or new lawns.
The best long-term approach for getting rid of these weeds is to weaken them through repeated hoeing and cutting. The key is to attack them before they flower, or at least before the flowers mature, as they will then have no opportunity to reproduce and so could disappear from your garden for the long term. However, be aware that some seed-propagated weeds, including dandelions, also have strong roots – and that they can spring back up from root material in the ground. For these weeds, a long-term solution means dealing with the roots as well.
Why do I need to get rid of weeds?
Because of their resilience and how rapidly they can spread, before long weeds will compete directly with your cultivated plants and food crops, depriving them of water, nutrients and light. So, while your perennials, shrubs and ornamentals have been carefully selected to grow where conditions are right, weeds simply spring up wherever they like. Your chosen species depend on the right care and environment to thrive, while weeds are altogether less picky and find it easier to spread. They also grow more quickly, are more resilient, and can introduce diseases and attract pests. So identifying them is the first step to restoring the balance in your garden, and if addressed early the weeds can be eliminated for good. What’s more, there’s no need to use weedkillers and herbicides.
Identifying and tackling weeds
The better you are at accurately identifying the weeds on your lawn and in your garden beds, the more targeted your approach can be. We have listed some of the most common types of weed and the ways in which they can be eliminated.
Identifying weeds: field bindweed (convolvulus arvensis)
Propagation type: Root
Characteristics: Climbs up other plants by winding itself around them; found throughout much of the UK. A very aggressive plant despite its pretty flowers.
Damage: Stunts the growth of other plants and overwhelms them.
How to tackle: Use a hoe to cut off any shoots above the ground or pull them up by hand. It takes a lot of patience to tackle this weed in the long term, as the slender rhizomes are long and difficult to remove from soil. However, if you repeatedly cut the weeds back during the gardening season, you will continuously weaken the deep roots and eventually exhaust the weed’s reserves. As it doesn’t generally spread overground, field bindweed can certainly be tolerated in secluded areas.
Benefit: No benefit
Identifying weeds: stinging nettle (urtica urens and urtica dioica)
Propagation type: Root
Characteristics: Stinging nettles come in a small (urtica urens) and a tall variety (urtica dioica). Both produce a unpleasant stinging sensation on contact with the skin.
Damage: Propagates quickly via roots and seeds.
How to tackle: Can be cut down with a brushcutter. Afterwards, use a garden fork to loosen the earth, and lift the roots of the weed to ensure that the weeds do not return. Note that all stinging nettle growth within an area of around one square metre comes from a single plant.
Benefit: Home-made nettle manure and liquid fertiliser are great for strengthening crop plants and combatting pests such as greenfly. Stinging nettles also provide essential habitat for some species of butterfly, as the caterpillars of admirals, the peacock butterfly and the small tortoiseshell butterfly feed exclusively on nettles.
Identifying weeds: gallant soldiers (galinsoga parviflora)
Propagation type: Seed
Characteristics: An annual weed that prefer sunny locations, also known as potato weed. Produces yellow and white flowers and large quantities of seeds. Dies off with the first frost
Damage: Spreads extremely quickly and can germinate the following year. Competes with other plants for light, water and nutrients.
How to tackle: Remove through regular hoeing or weeding, ideally while the weeds are still young, so they cannot flower and mature.
Benefit: No benefit
Identifying weeds: ground elder (aegopodium podagraria)
Propagation type: Root and seed
Characteristics: Persistent perennial weed producing many seeds, and with roots that can regenerate. Grows up to 80 centimetres tall. Spreads quickly and must not be composted with seeds or roots, as these will sprout in the compost. Creamy-white umbels of flowers.
Damage: Deprives other plants of nutrients and space.
How to tackle: Lift the weeds out of the soil with a digging fork to remove them. Persistent weed.
Benefit: No benefit
Identifying weeds: creeping buttercup (ranunculus repens)
Propagation type: Root
Characteristics: Also known as crowfoot, buttercup thrives in damp meadows and water’s-edge locations. In dry conditions the yellow flowers may become nut fruits, but most dissemination is by underground runners. Buttercups thrive in acidic soil.
Damage: Spreads extremely widely and robs other plants of space. It can be especially problematic on lawns, as it suppresses growth of grass.
How to tackle: As buttercups prefer acidic soil, the grass can be bolstered and the weed weakened by spreading lime to change the pH. Regular mowing, particularly during the flowering period, also prevents seed formation. Digging up is the most effective long-term approach; pulling up the roots is best, but as they are extensive it may be difficult, and can also cause holes in the lawn.
Benefit: In small doses the buttercup may be tolerated as a guest in the garden, as the yellow flowers are a beautiful addition.
Identifying weeds: shepherd’s purse (capsella bursta-pastoris)
Propagation type: Seed
Characteristics: Produces rosettes of leaves and very small flowers. The seeds can survive for long periods, remaining dormant for up to 30 years.
Damage: Competes with other vegetation (including grass) for nutrients. Transmits the pathogen clubroot, which attacks the roots of other plants and damages them.
How to tackle: Remove shepherd’s purse and destroy it before the seeds mature.
Benefit: No benefit
Dandelion (taraxacum)
Propagation type: Seed
Characteristics: Yellow flowers which mature to form the familiar dandelion clock. Seeds can germinate for up to 10 years.
Damage: Spreads extremely quickly and far thanks to wind-borne seeds. Also regenerates easily due to its strong taproot.
How to tackle: Mow the lawn, pull up the plant and deal with it before flowers mature.
Benefit: A well-known wild herb, with all parts edible.
Identifying weeds: couch grass (elymus repens)
Propagation type: Root
Characteristics: Vigorous perennial weed. Rhizomes may be as deep as 10 centimetres underground. Needs lots of light.
Damage: Suppresses other vegetation and grasses and damages lawns. Also occurs in perennial beds.
How to tackle: There are different ways to tackle couch grass depending on where it occurs. You can cover the affected areas with cardboard to starve the light-hungry rhizomes. This method takes some time, so you may wish to conceal the covered areas with compost. Removing the weed by hand is very laborious, but often successful. Another method is to plant potatoes in affected beds: the dense leaves will soon deprive the rhizomes of light.
Benefit: A pioneer plant, which means a hardy species that can grow on thin soil and in barren environments where most vegetation cannot survive.
Identifying weeds: chickweed (stellaria media)
Propagation type: Seed
Characteristics: Flowers almost all year round and has very small, white flowers. Annual, herbaceous plant. An internal section of the shoot is often left behind when the plant is pulled up.
Damage: Does not cause much damage, but consumes a lot of nutrients and can choke out smaller vegetation.
How to tackle: The shallow roots are easy to pull up with the plant. You should always replant and mulch lawns and garden beds quickly after removal, as a preventive measure. Because chickweed prefers soil that is low in nutrients, fertilising may also help.
Benefit: As a pioneer plant, it protects barren areas from erosion.
Identifying weeds: field horsetail (equisetum arvense)
Propagation type: Root
Characteristics: Field horsetail likes damp, compacted clay soil and a rather acidic environment.
Damage: Chokes out other plants and is difficult to weed out.
How to tackle: Improving the soil is the first step, as the weed favours typically poor conditions, thriving in compacted ground in particular. Improving aeration and preventing waterlogging will keep the weed from spreading. Cut the plant back repeatedly and add sand and compost to loosen and gradually improve the quality of the soil.
Benefit: Contains a lot of silica and can be used as a remedy for fungal diseases.
How to dispose of and destroy weeds
There are a number of ways to dispose of weeds. If the plant has already flowered and matured it should not be composted, as the seeds usually survive composting and can then germinate again when the compost is added to soil.
In addition, you should always compost weed roots with care. Start by identifying which weeds propagate via roots, and don’t add those roots to your compost. They can go in a garden bin for industrial composting. For other weeds, make sure the roots are chopped up before composting, otherwise you may simply be adding a viable plant to your compost heap. Weeds which have flowered may also produce seed that can germinate, so you should only compost young weeds that haven’t flowered.
With those caveats in mind, composting weeds is the best thing to do, as they break down to valuable nutrients that will certainly prove useful.
The best way to dispose of large volumes of weeds that cannot be composted is to put them into the appropriate waste disposal, e.g. at a recycling centre or a local green waste collection facility. You can dispose of smaller quantities of weeds in your domestic organic waste. This also applies to seed-propagating weeds and roots, as it will ensure that they cannot germinate or sprout again.
Bee-friendly meadows: where weeds become friends
Bear in mind that, although we may find weeds unwelcome in our gardens, bees and other creatures enjoy the welcome variety they offer. The flowers of many types of weed are a good source of nectar for them, so consider leaving some of the uninvited guests in place if you can.
Summary: identifying and eliminating weeds
- Weeds are plants that spread quickly and are not wanted on the lawn or in the garden
- Generally, weeds are separated into types spread by seeds or by root material
- Seed-spreading weeds should be cut back at an early stage, before seeds can be produced
- Root-propagating weeds can spread throughout a large area by means of their root rhizome systems: an entire plant can grow from small fragments of root. The most effective way to tackle root-propagating weeds is to pull them up and remove their roots from the soil
- The more precisely you can identify the type of weed, the more targeted your approach can be in tackling it. Differentiating between root-propagating weeds and seed-propagating weeds is a good way to determine how to combat a weed effectively, and necessary in the long-term fight against weeds
- You can dispose of weeds by composting them, adding them to your garden waste collection or, for larger quantities, taking them to an appropriate recycling centre or green waste collection facility
