Win the weed war

It can feel like you’re fighting a losing battle against these unwanted intruders. But there are ways to tackle them

STINGING NETTLES

PROFILE: Well-known for their painful sting, these weeds are widespread. They produce a dense mat of bright yellow roots and form thickets of erect stems more than 1m tall. The green serrated leaves are covered with stinging hairs and brown tassel-like flowers appear from early summer onwards.

STRATEGY: While you may want to dig up and eradicate the weed with polythene and mulch, it’s useful to know that nettles are indicators of fertile ground. Ensure you wear gloves to protect the skin and pull the plants up by the root. Make sure you get the underground portion or the weed will come back.

GROUNDSEL

PROFILE:

A native annual, groundsel flowers and sets seed throughout the year. Even seeds that have been buried in soil for up to six months will germinate when exposed to light.

STRATEGY: It’s important to grub out the weeds before the small yellow flowers and fluffy seed heads appear. Left to get a foothold, the leaves become host to rust fungus, which can spread to cultivated plants.

BINDWEED

PROFILE:

It produces thread-like vines that wrap tightly around plants, and eventually strangles them. It’s easy to spot with its trumpet-shaped blooms, but don’t be tempted to leave it because soon after the first flush of flowers are over, it will take over and ruin your garden.

STRATEGY: It takes patience and willpower, and several attempts to pull it up, as any root left behind will resprout. Cutting the vine back when it appears will weaken it and eventually cause it to die off.

SHEPHERD’S PURSE

PROFILE: This has been used as a medicinal herb since ancient times. It was also used by soldiers on the First World War battlefields to stop bleeding. It’s a prolific weed, growing in sun or shade and on most soils. STRATEGY: From a rosette of hairy leaves, it sends up flowers on tall stems, followed by purse-like pods, which hold up to a dozen seeds. Seed buried in the soil can remain viable for years, so aim to pull weeds up before they flower or regularly hoe seedlings soon after they appear to sever rosettes from their taproots.

HAIRY BITTERCRESS

PROFILE: This edible weed is super-efficient. It is able to complete its life cycle in less than a month and disperse thousands of seeds from the spring-like seedpods. It grows anywhere and everywhere, from bare soil to walls, and is often imported in potted plants bought from garden centres, which can go on to infest an entire garden. STRATEGY: To control its spread, it’s essential to pull up the young plants before they get a chance to flower and set seed. This occurs from March to August. Cultivating the soil will bring up new seeds, although mulching will help to prevent them from germinating.

CHICKWEED

PROFILE:

Chickweed produces several generations that grow, flower and produce seeds before dying. It can be a problem on vegetable plots, which are cultivated regularly, but is a good indicator of high potassium, nitrogen and lime levels and low phosphate. It’s one of the first weeds to wilt when soil is dry.

STRATEGY: Hoeing on dry days when the seedlings are small can be effective, while on wet days, pulling weeds out by hand works best.

COUCH GRASS

PROFILE: This is a nightmare weed that produces a vast network of underground stems and roots that travel through the soil, pushing up new shoots every 5-10cm along their length. Watch out for newly emerging tufts of grass because instead of dying at the end of each season, they keep on going through the winter and beyond. STRATEGY: Be extra vigilant, pulling up shoots because any pieces remaining will resprout. To clear, cover soil with thick black polythene for a couple of seasons to exclude light.

DANDELION

PROFILE: Dandelion’s thick taproots delve deep into the soil and cracks between paving, making them tricky to remove. If tiny pieces of roots remain after cultivating the soil, they’ll resprout and take over. STRATEGY: It’s best to dig them out with a fork, especially before the bright yellow daisy flowers turn into fluffy ‘clocks’ and release their airborne seeds. A plastic sheet mulch will prevent dandelions getting a foothold, but you may find them useful for draining waste ground and make use of their edible vitamin-rich leaves in salads.

CLEAVERS

PROFILE: Owing to being covered by bristly hooked hairs, the stems and seeds of cleavers are sticky, which allows it to scramble around the garden and spread further afield by hitchhiking on to animal fur and clothing. STRATEGY: Seeds take just two months to become established plants, so in flower beds aim to grub them out as soon as the seedlings emerge and before they flower in mid-spring. Mulching weed-free soil with a 5cm layer of composted bark will help to suppress the seedlings.

JAPANESE KNOTWEED

PROFILE: When the tall bamboo-like stems of this weed emerge in spring, they’re capable of bursting through tarmac and concrete. Below ground, this indestructible thug gets busy producing thick, woody rhizomes that spread quickly in all directions. STRATEGY: Even tiny fragments that break off can regrow, making it almost impossible to eradicate. By law, it’s an offence to plant or cause Japanese knotweed to grow wild in the UK. Even dumping contaminated soil and garden waste at the tip is a risk. If you think you have it, go to gov.uk/ guidance/prevent-japaneseknotweed-from-spreading.