What to do with garden waste

More than people expect, and heavier. Clearing an overgrown border, lifting a patio or taking down a fence generates far more than a few garden bags, and a lot of it weighs a surprising amount. A single cubic metre of soil comes in at roughly a tonne to a tonne and a half, so the spoil from one raised bed or a modest patio dig can outweigh everything else on the job put together.

The other thing that catches people out is that the waste is not one material. Light prunings, dense soil, old treated timber, broken slabs and the occasional regulated item all need handling differently, and mixing them together makes every one of them harder and more expensive to deal with. Deciding where each stream goes before you start, rather than facing a mixed heap in the driveway at the end, is what keeps a project moving. The rest of this guide takes those streams one at a time.

This is the one plant that changes what you are allowed to do with your soil, so it is worth knowing on sight. In summer it grows fast into tall, bamboo-like canes, often with purple speckling, carrying bright green leaves shaped like a shovel or a heart that come off the stem in a distinct zigzag. Late in the season it throws out sprays of small creamy-white flowers, and in winter the canes die back to brittle brown stalks. If you are not certain, get it identified before you move any soil, because the roots spread underground and a small fragment is enough to start a new plant.

If you do have it, soil or plant material contaminated with knotweed may be classed as controlled waste, and it must not go in your green bin, your household bin, or a compost heap. If you cannot deal with it on site, it has to go to a landfill or incineration site that holds the correct permit, moved by a registered waste carrier, as set out in GOV.UK guidance on preventing knotweed from spreading.

On the law, having knotweed on your land is not itself an offence, and you are not forced to remove it. What you must not do is cause it to spread into the wild, which is an offence under section 14 of the Wildlife and Countryside Act 1981. Moving contaminated soil off site carelessly, or letting cuttings escape, is exactly how that happens. Between the disposal rules and how readily it regrows, most people treat knotweed as a specialist job rather than something to tackle alongside the ordinary garden clearance.

Often, yes, and this is worth checking before you assume it is free. Garden waste collection is not a service every council has to provide, so it varies widely. GOV.UK notes there may be a fee for it, and in practice many councils run it as a paid annual subscription with a wheelie bin or sacks, while some include a limited amount and others do not collect it at all.

The recycling centre is the usual free route for household quantities brought by car, but it comes with its own conditions that catch people out. Many centres limit how much soil, rubble or bagged waste you can bring, ask you to book a slot in advance, or require a permit if you turn up with a van or a trailer rather than a car. It is worth a two-minute check of your own centre before you load up. Note that the GOV.UK collection tool covers England and Wales, and Scotland and Northern Ireland arrange their collections separately.

A shed, deck, greenhouse or run of old fencing coming down is really construction waste rather than garden waste, and two materials in older structures deserve genuine care rather than a quick skip run.

The first is asbestos. It was used in cement panels, corrugated roofing sheets and some old shed and garage cladding right up until it was banned in 1999, so anything built or re-clad before 2000 could contain it. The safe approach, following HSE advice, is not to break, drill, cut or sand anything you suspect. Material that is in good condition is usually safest left intact, and if it genuinely has to come out you should keep it damp and unbroken, get it assessed, and deal with it as hazardous waste through your council rather than the ordinary tip. Do not try to remove it yourself if you have had no training for the work. This is a real safety point, not a box-ticking one, and it is worth pausing over before you put a bar through an old panel.

The second is old creosote-treated timber, the kind of fence panel, post or railway sleeper with a dark, oily surface and a strong tarry smell. Creosote has not been sold for amateur use since 2003 and is now restricted to professional treatment. The rule that matters at home is not to burn it: only untreated wood may be burned under the GOV.UK D7 waste exemption, so treated or painted timber goes to a recycling centre or a licensed carrier, never on a bonfire.