Are these the 5 hardest weeds to shift? Here's how to get to grips with them this weekend

Weeds. They’re as much a part of gardening as flowers, fruit and veg, but that doesn’t mean you have to love them. If you’re struggling to keep ahead of them this year in your garden, here’s our rundown of nine of the rowdiest uninvited guests – and what you need to know.

1: Dandelion (Taraxacum officinale)

How it spreads: With hundreds of devilishly airborne seeds – and tricky, fragile tap-roots.

Should we leave dandelions for wildlife? Yes and no. Whilst dandelions offer nectar for bees, they are fecund weeds that can create a headache. An established clump could produce 12,000 seeds in one year if the plants are not deadheaded after flowering.

How else can I help bees? Grow non-maddening plants that bloom at roughly the same time, such as lungwort (Pulmonaria).

Why are dandelions hard to kill? Their long tap roots are hard to excavate in one piece. If you don't dig down deep enough, the dreaded snap sounds as you yank out the plant; even if the root piece left in the soil is only an inch long, it can produce new dandelions. After they've flowered, the clocks (seedheads) distribute a cloud of seed when the wind blows.

2: Running bamboo (Phyllostachys)

How it spreads: Via rhizomes that run and run.

Is bamboo a weed? Some types can become weeds if not contained by a root barrier. The ones to avoid, or at least be careful with, are the 'running' forms, including those from the genus Phyllostachys. Whilst they produce beautiful culms (canes), over time, some species (such as Phyllostachys bissetii) can cause as much havoc as Japanese knotweed.

Which bamboo is best to grow? The clumping (non-spreading) forms (such as those from the genus Fargesia) are excellent, providing a low-maintenance mass of rustling evergreen leaves and architectural canes, without becoming invasive.

Why is running bamboo hard to kill? Because once it reaches maturity (which could take a decade), it produces long, vigorous underground rhizomes that can appear several metres from the parent plant, sending up new culms, which can pierce driveways and even foundations. Sections of rhizome left in the ground can form new plants. Its vigour depends on conditions: in cold regions and poor, dry soil, running bamboo often behaves itself. In warm, wet conditions, get ready for a battle.

3: Stinging nettle (Urtica dioica)

How it spreads: Spreading roots and stems, above and below the soil.

Should we leave nettles for wildlife? Yes and no. Many butterflies – including red admiral and comma – rely on stinging nettles in a sunny spot as food plants for their caterpillars, but nettles are rampant weeds that coat the ground at speed. Nettles are harmful to dogs if eaten.

How can I provide nettles for butterflies? The best approach is usually to remove nettles where you don’t want them – wear gloves and other protective clothing – but leave a big corner where they can thrive in the sun, and deliver all those wonderful wildlife benefits.

Why are nettles hard to kill? Because they colonise large areas (especially moist, rich earth in full sun) via horizontal rooting stems and spreading underground rhizomes, as well as seed. Although they don't grow deep, they can regenerate from a small section of rhizome left in the ground.

4: Creeping thistle (Cirsium arvense)

How it spreads: Wind-blown seeds, and creeping roots and stems.

Is it best to leave thistles for wildlife? That depends on the thistle. Creeping thistle is a nectar source for bees and butterflies, while birds eat the seeds and use the soft thistledown to line their nests. But it's so vigorous that it's listed in the UK's Weeds Act 1959 (which protects agricultural land) and considered seriously invasive in the USA, Canada and New Zealand, so think twice about courting it in your garden.

Are all thistles invasive? No. Prickle-free Cirsium rivulare 'Atropurpureum', with its wine-magenta blooms that bumblebees love, is superb in UK gardens. In the USA, opt for native thistles Cirsium pumilum and Cirsium discolor.

Why is creeping thistle hard to kill? Its roots and rhizomes spread fast and deep underground and re-shoot from small pieces left in the soil. The seedheads (each one composed of up to 200 seeds), scooped up by the wind, become thistledown that can travel great distances.

5: Couch grass (Elymus repens)

How it spreads: Underground stems

What does couch grass look like? It sends up flat, soft-green blades that can reach 40cm, from pale sheaths. Also known as twitch grass in the UK or quack grass in the USA, it's fast-growing and produces tall flower spikes in summer.

Is couch grass good for wildlife? Yes, it's great for moths and butterflies, but confining it to a wild patch of garden is wise.

Why is couch grass hard to kill? Its pale rhizomes creep through the soil, knitting around the roots of other plants. Pieces of rhizome left in the ground can form new plants, and the seed is capable of remaining viable underground for years.