Weeding is one of the biggest and most time-consuming jobs in the garden, and while some gardeners find it quite satisfying and therapeutic, many of us probably feel that we have better, more enjoyable things to do.
You may also like
- Weeds can help gardeners adapt to a changing climate
- Can we cope with allowing our gardens to go wilder?
- The new lazy way to garden makes it east to manage
Some weeds spread faster and are more difficult to remove than others, so to help you out, here we pick the 10 weeds to tackle as soon as you spot them, and highlight another 10 that are unproblematic, great for wildlife and really quite pretty, that you could just leave to grow.
The 10 worst garden weeds
These are the worst perennial weeds for gardeners as they spread aggressively, entangling or smothering weaker or smaller plants or seedlings and outcompeting them for water and nutrients. They may have a combination of deep, spreading underground root systems, deep tap roots, long twining stems, strong growth and self-seed easily. They can be particularly tricky to remove and can regrow from a tiny section of root left behind in your soil.
Japanese knotweed
This perennial weed has bamboo-like stems, heart shaped leaves and tasselled cream flowers. Reynoutria japonica was originally introduced to the UK as an ornamental plant, but it spreads via invasive roots that can be more than 1m deep. It is listed as an invasive non-native plant on Schedule 9 of the Wildlife and Countryside Act 1981. It can grow through cracks and weaknesses in paving, tarmac and asphalt.
Control: Hire a professional company that specialises in the removal of invasive weeds.
Ground elder
Ground elder (Aegopodium podagraria) is an invasive weed that quickly forms a dense mat of roots and a carpet of leaves. It's particularly problematic in borders as its roots can creep between other plants, making it hard to remove, and it will soon outcompete smaller or less vigorous plants. It can also make it difficult to plant new plants. Ground elder is capable of re-growing from only small pieces of root, which makes it hard to eradicate – don’t compost them in your home compost bin, as you may unwittingly spread them back around the garden.
Control: Try pulling off or cutting the stems – if this is done repeatedly, it will weaken it. You could try digging out the roots, but take care not to damage other plants (a hori hori knife is useful for this) and to dig out as much root as possible so that it can’t regrow. If the weed is really established, you could dig up all of the plants from the border, dig out as much ground elder as possible and replant. This is a good job for winter, when many perennials are dormant. You could also try smothering plants, covering with a compostable material such as cardboard or with a weed membrane.
Bindweed
There are two types of bindweed – field bindweed (Convolvulus arvensis) and hedge bindweed (Calystegia sepium). Hedge bindweed is the most problematic. The stems can reach up to 3m long, trailing across the ground or twining their way up the stems of tall plants. The funnel-shaped flowers are about 5cm wide and appear from June to September; they are usually white. The pale roots can reach 4m deep, so it can be very hard to remove them all, and they regrow from a tiny segment. Field bindweed (Convolvulus arvensis) is less problematic than hedge bindweed. Its trailing or twining stems don’t usually extend beyond 1m.
Control: Dig out the roots as deeply as you can using a weeder, hori hori or even a spade and carefully trace the root down as far as you can in order to remove as much as possible; smother with mulch, cardboard or a weed membrane.
Green alkanet
With its pretty deep blue flowers reminiscent of forget-me-nots, it’s easy to see why green alkanet (Pentaglottis sempervirens) was originally introduced as an ornamental plant more than 300 years ago. It can be a useful plant for ground cover in moist, shady areas of the garden, and its nectar-rich flowers are attractive to pollinators, but it can be invasive if it gets a hold in your borders – it spreads easily, self-seeds readily and its large leaves can smother smaller plants. Its deep taproots make it hard to remove.
Control: Deadhead plants before they have a chance to set seed, and don’t put any fragments in your home compost. You can also dig up seedlings as they appear, ensuring all of the deep taproot is removed. Any root fragments left behind can regenerate.
Horsetail
A relic from the age of dinosaurs, this perennial weed is astonishingly resilient. Its rhizomes can penetrate more than two metres into the soil, enabling it to resurface even after determined digging. Horsetail (Equisetum arvense) quickly forms dense carpets, outcompeting other plants and even pushing up through tarmac and paving. It spreads via rhizomes which can be as much as 2m deep, as well as via spores.
Control: Pull or cut off new growth as soon as it appears - over time, this will weaken the plants. You can also try forking out the rhizomes, making sure no trace is left behind; do not put these on your compost heap but add to the council green waste bin instead. You could also try smothering plants with a compostable material such as cardboard, then layering a deep layer of mulch (such as garden compost) on top. In lawns, frequent mowing can weaken horsetail over time, though it rarely eradicates it.
Three-cornered leek
Allium triquetrum was originally introduced as an ornamental, and this member of the allium family is charming in flower but insidious in habit. Its ability to form dense colonies via a network of tiny bulbs makes it difficult to eradicate in a border. It spreads via tiny bulbils, and seeds, dispersed around the garden by ants.
Control: Dig out the seedlings, ensuring that all of the bulbils are also removed, or dig out whole clumps with a spade.
Couch grass
This fast-growing grass looks very similar to the grass growing in your lawn (and may well be growing there) but it is more vigorous, produces a dense mat of rhizomes and has blades that can reach around 40cm tall. Elymus repens comes into growth very early in spring, and you may notice tufts of it in flowerbeds (especially those edged by lawns), bare soil and cracks in paving. It spreads via rhizomes and via seeds.
Control: Dig out, making sure to remove as much root as possible. Regular mowing will suppress its growth in lawns. You can also smother it, using a layer of cardboard topped with 20cm of mulch.
Creeping buttercup
The pretty, bright yellow flowers of creeping buttercup (Ranunculus repens) are great for pollinators and look pretty growing in a wildflower meadow or area of long grass. However it does have a tendency to spread via runners and roots and can be unwelcome in some parts of the garden.
Control: In a lawn, frequent mowing should keep it under control. Keep the lawn well aerated, and rake before moving to lift out the runners. Deadhead flowers before they set seed. In a border, get out plants, taking care to remove as much of the root system as possible. You can also try smothering them with cardboard and a 20cm layer of mulch.
Brambles
Brambles (Rubus fruticosus) are one of the best possible plants for wildlife and their blackberries are delicious eaten raw, or cooked in crumbles, jams and pies. However, they have long, fast-growing and thorny stems which root at the tips and can quickly form thickets, so they are not welcome in cultivated parts of the garden.
Control: Mulch borders in late winter or early spring. Pull out seedlings as soon as you spot them, before they have a chance to establish. If stems are creeping into your garden from neighbouring gardens, cut back the stems regularly.
Pendulous sedge
Pendulous sedge is a tufted, evergreen plant that forms dense clumps of up to 1m tall and wide. It self seeds easily and thrives on damp soil. Arching flower stems appear from within the clump in May and June. They can reach 1.4m and bear drooping, catkin-like spikes of yellow-brown flowers.
Control: Remove the flowering spikes to prevent self seeding and dig up seedlings when you spot them. Alternatively, dig out large plants – this can be quite a job.
The 10 weeds you really don’t need to worry about
If perennial weeds are in your borders, veg patch or lawn you may want to remove them, but you could allow some less pernicious weeds to grow in the wilder areas of your garden, on an unmowed or flower-rich area of grass, on steep banks or under trees or hedges.
Consider leaving these ‘weeds’ in your garden – they are mostly shallow rooted, are not hugely invasive so rarely become a problem and are beneficial to a wide range of wildlife. They are actually wildflowers, and if you reframe them as such, they could be welcome additions to your garden.
Chickweed
Chickweed can quickly form a carpet on bare soil, but it is shallow rooted and easily removed, and its leaves are edible. Its flowers provide nectar for bees and its seeds are eaten by small birds.
Dandelions
The pollen-rich flowers of dandelions are extremely attractive to bees and butterflies, and are produced over a long period of the year and the seedheads are eaten by several birds. The young, tender leaves have a peppery taste and can be added to salads.
Clover
There are several species of clover that you may find in your lawn, including red and white clover, and they are great for pollinators. They may be considered unwelcome in a tended lawn, but they are likely to become increasingly useful in gardens as they are drought tolerant, staying green when your lawn grass is turning brown.
Speedwell
There are actually four species of speedwell that can be spotted in gardens. They are all low-growing plants with pretty blue flowers. They can provide nectar for solitary bees, and are a food plant for heath fritillary butterfly. Speedwells can be unwelcome in a manicured lawn but are rarely problematic in borders.
Herb Robert
This annual or biennial plant has geranium-like magenta flowers, red tinged stems and pretty foliage and is on the RHS Wildflowers for Pollinators list. It self seeds easily but is easily dug up if needed.
Daisy
Daisies have pretty flowers almost all year round, making them very useful for insects at times of the year when there are fewer flowers around.
Teasel
The flowers of teasels are loved by bees and the seedheads are loved by birds, especially goldfinches. Rainwater also gathers where the whorls of the leaves meet the stem – providing a useful source of water for thirsty wildlife.
Dove’s foot cranesbill
Dove’s foot cranesbill has pretty geranium-like flowers and lobed leaves. While you may not want it in a fine lawn, elsewhere it is a pretty wildflower that is attractive to pollinators.
Willowherbs
The tall pink spikes of willowherbs such as rosebay willowherb, have nectar rich flowers and leaves that are a food source for the giant hawk moth as well as other invertebrates; they can look very attractive in a naturalistic border. They are easy to pull out if they are becoming a problem; or deadhead before they have set seed.
Bittercress
There are several types of these native wildflowers that are beneficial to moths and butterflies. As its name suggests, the leaves are edible and have a peppery taste and can be added to salads.
What is a weed anyway?
Before you bring out the hoe, trowel or hori hori knife, it’s worth bearing in mind that a ‘weed’ is simply a plant in the ‘wrong’ place; the weeds in your garden can actually tell you a lot about your plot’s history and unique ecology. Weeds are essentially wildflowers and can provide shelter, food and habitat for wildlife such as bees, butterflies and birds, plus a myriad of insects, which can in turn boost the biodiversity of your garden and reduce the number of unwanted insect ‘pests’.
Recent studies have shown that creeping buttercup, for example, is visited by 240 wildlife species, and brambles (blackberries) by 207. So it’s worth thinking about whether they are really a ‘problem’ where you are finding them in your garden; can you find a balance of wild and cultivated?