Types of Wood Chippings: What Your Garden Project Needs

Key Takeaways

• Bark chippings and wood chips are not the same product. Bark contains no wood and holds its colour for years; wood chippings are the tree itself, and the colour fades within a year or so.
• Hardwood chippings are the default for paths, borders and chicken runs – they hold their colour far longer than softwood, and don’t breakdown nearly as fast.
• Softwood chips are the budget buy for covering big areas, but age fresh conifer chips for a few months before mulching near young plants.
• Wood chip mulch needs 5 – 7.5cm of depth to suppress weeds, and 7.5 – 10cm to hold moisture through a dry spell. A thin scatter will just slowly compost.
• In a planted border, wood chips go straight onto the soil. Save the membrane for paths, where nothing is planted to grow through it.
• Smell a delivery before you spread it. Good wood chippings smells of cut pine or damp earth; vinegar, ammonia or rotten eggs means the load has gone sour, and sour mulch kills young plants.
• Refresh a tired-looking layer with about 2.5cm every two or three years, but never stack a full new layer on top of the old one unless it has significantly decomposed.

I get asked the bark-or-wood-chip question more than almost anything else in this category, and the person asking has usually already bought the wrong one. A couple of springs back I was called to look at a client’s border where every new shrub had scorched leaves and half were dropping. They were blaming the nursery. The culprit was the mulch: a trailer-load of fresh arborist chips, spread the same week they were cut, and when I turned the leftover pile with a fork the smell of vinegar nearly knocked me over. The plants recovered. The cost of replacing the ones that didn’t wasn’t small.

This page is the fix for that kind of mistake before it happens. Below is every type of wood chip you will find in the UK, what each one is for, and the checks I make before any load of mine goes on a client’s garden.

What Is the Difference Between Wood Chips and Bark Chippings?

Wood chips and bark chippings are different products from different parts of the tree, and mixing them up is the most common buying mistake. Bark is the outer layer only – no heartwood – separated at the mill and ground into grades. Wood chip is the wood itself, straight out of a brush chipper: arborist waste, milling by-product, or forestry timber. Last, and definitely least, there’s chipped recycled pallets.

Why it matters at the checkout rather than just in a textbook:

1. Colour. Wood chips lose their fresh colour a lot faster than bark. If you want a border that still looks fresh in two years, bark wins. If you are covering a big working area and do not mind the way they fade, wood chip is cheaper.
2. Staying put. Chips and coarse bark laid straight onto soil hold their moisture and their weight, and they stay where you put them. The same material sitting on a sheet of fabric dries out, lightens, and ends up blown across the lawn with the birds flicking the rest. New bark will shed the first rain or two off its back as well; once it has weathered, it takes water up. So: put soil under mulch in planted borders. I only use a membrane for a wood chip path, because I want nothing to grow through it.
3. The cheap-bag problem. Budget bark is often padded out with wood shavings, which rot fast and look worse. It feels more like hamster bedding than chipped bark, so go for quality.

I do the full bark-side version of this page – grades, nuggets, pine versus composted – in bark chippings for garden use. The broader comparison, covering compost, straw, manure and the rest alongside bark and chip, is in my guide to what is mulch. Everything below is the wood chip half.

Types of Wood Chips for the Garden

TLDR: hardwood for anything you want to last, softwood for cheap coverage, certified play chip for anywhere children fall, and compost mulch when the soil matters more than the looks.

There are four types of wood chips for landscaping that I spend money on, plus a couple you will see advertised that need a word of caution.

Hardwood Chippings

Hardwood chippings are the ones I reach for by default. Mixed hardwood – typically oak, beech, ash and birch – is dense, slow to break down, and keeps a tidy surface underfoot, which is why it is my pick for permanent paths, perennial borders and anywhere that gets walked on. It is also the only chip I will put in a chicken run: softwood soaks up the mud, and bark can grow moulds that do real harm to poultry. The full reasoning is in my guide to wood chip for chicken runs.

Softwood Chips

Softwood chips – mostly pine, sometimes spruce or larch – are the economical option, and they break down faster, which is either a flaw or the whole point depending on the job. Worth knowing before you shop: unlike hardwood chip, which often comes labelled with the species mix, softwood is nearly always sold by grade and job rather than by species, and what you get depends on what the mills are cutting that time of season. Ours is mostly pine. If you see larch offered, it will usually be local trade material from forestry work, and it is also good stuff.

Certified Play Chip

Play chip is wood chip that has been screened and tested for use under swings, slides and climbing frames – in the UK that means tested to BS EN 1177 for impact absorption, with the safe depth set by the fall height of your equipment. I do not advise improvising this one with garden-grade chips, and I would always ask to see the compliance certificate. Our play chip comparison puts the hardwood and softwood play grades side by side, and the play bark calculator works out the depth from your equipment height. Our play chip comparison puts the hardwood and softwood play grades side by side, and the calculator works out the depth from your equipment height. We carry both certified grades, and for a back-garden play area certified play chip is the cheaper buy.

Compost Mulch

Compost mulch is well-rotted wood chip – the breakdown has already happened in the pile instead of on your border, so it feeds the soil from day one without the nitrogen argument that fresh wood brings. It is the type I use when the task is improving tired ground rather than dressing it: around trees and shrubs, vegetable beds, and new planting on poor soil. The grades we carry are compared in the compost mulch range.

Sawdust and Wood Shavings

Sawdust and shavings are the two to be careful with. They are sold cheap, and they are the worst nitrogen thieves of the wood family – thin softwood shavings worst of all. If you want a wood-based mulch, choose chips over shavings every time; keep shavings for animal bedding, and compost them for six months before using around your garden.

Coloured Wood Chips

Coloured chips and dyed mulches are mostly a bark product in the UK, and the dyes themselves are usually iron-oxide or carbon based and safe enough. The thing to check is what is underneath the colour, because poisonous recycled pallet timber is a common base. I have covered the whole question, including how they are made and what to look for, in my coloured bark guide.

Wood Chips as Mulch: Are They Actually Any Good?

Wood chips make a genuinely good mulch – with two conditions attached that the glowing versions of this answer tend to skip. Laid at proper depth on bare soil, a chip mulch suppresses weeds, holds moisture through a dry spell, evens out soil temperature, and feeds the ground as it slowly breaks down. The conditions:

1. Depth does the work. 5 – 7.5cm minimum for weed suppression, 7.5 – 10cm if holding moisture is the point. A 2cm scatter looks nice for a month and does nothing.
2. On the soil, not in it. Chips sitting on the surface borrow almost no nitrogen from established plants. Chips dug into the soil are a different story – the microbes breaking them down will strip nitrogen from your beds while they work. Mulch with them; do not rotavate them in. If a mulched border does yellow in its first season, that and nine other problems are covered in my bark and woodchip mulch fixes.

And when the surface fades – which chips do sooner than bark – resist the annual top-up habit. Add about 2.5cm every two or three years to freshen the look. Stacking a full fresh layer on the old one is how borders quietly end up at 12 to 15cm and the shallow-rooted plants choke.

How Deep Should Wood Chippings Be?

Wood chippings need different depths for different jobs, and depth is the single number that decides whether the stuff works. My working figures:

Play areas are the exception where the depth is not a preference but a safety figure, set by the critical fall height of the equipment under BS EN 1177 – the bark and wood chip calculator has the fall-height table and will size the whole order, bags included, from your measurements.

Fresh or Aged Wood Chips: Which Should You Use?

Aged chips are the safer buy for planted areas; fresh chips are fine for paths and clear ground, and that distinction is the whole answer. Fresh arborist chips – the kind you can get cheap or free from tree surgeons – are green, sappy, sometimes hot in the middle of the pile, and occasionally carrying whatever the tree came down with. Let a delivered heap sit and breathe for a few months before it goes near planting, and turn it if you can.

Free chips deserve their own caution. A wildcard load from a tree job can be excellent, and it can be full of green leaf, shredded brash and the odd bit of plastic – you take what the chipper ate that morning. I am not against them; I am against spreading them the week they arrive around anything you paid good money to plant.

And whatever the source, use your nose before you use your fork. A healthy load smells of cut wood or damp earth. Vinegar, ammonia or rotten-egg smells mean the pile has gone anaerobic – sour mulch – and it will scorch soft growth on contact. Spread it thin somewhere out of the way, let the air at it, and the smell goes in a week or two. What sour mulch does to plants, and how to tell it from drought damage, is in the mulch problems guide.

How Long Do Wood Chippings Last?

Wood chippings outlast their looks – that is the number one thing to understand about their lifespan. The colour fades well before the chip itself has broken down, hardwood holds both its shape and its shade far longer than softwood, and a coarse chip outlasts a fine one on any surface. So judge a layer by depth, not by colour: rake it over first (it often revives the look for free), and if it genuinely has thinned, top up with roughly 2.5cm every two or three years. Replacing a whole layer because it went grey is throwing money on the border and risks suffocating your plants.

What Are Wood Chips Used For?

Wood chips get used for mulching, paths, driveways, play surfaces and animal runs – and each of those jobs has its own guide on this site, so I will keep this to the map:

• Borders and mulching: the how-to is in laying bark and chips, and the depths are in the table above.
• Paths: hardwood chips over a membrane, 7.5 – 10cm – full build in the wood chip path guide.
• Driveways: possible, with caveats and a proper sub-base – see the wood chip driveway guide.
• Play areas: certified chip only, sized by fall height – start with play bark vs garden bark.
• Chicken runs: hardwood only – the chicken run guide explains why the alternatives cause trouble.

Next Steps

If you have got as far as measuring up, the bark and wood chip calculator will turn your dimensions into an exact order, settlement allowance included. We carry hardwood and softwood chips, certified play grades and compost mulch in builders, bulk and jumbo bags with nationwide delivery – the full range is in our wood chips category. If your job is an odd one, get in contact and we will spec it with you.

If you would rather talk your wood chips through with a person, ring Outdoor Aggregates on 0330 043 7585. The office is open 7am to 7pm, seven days a week.

Have you used wood chip around the garden? What did you use it for, and how did it break down over time? Tell us in the comments.

FAQs

Do wood chips stop weeds?

Wood chips at 5 – 7.5cm suppress most annual weeds by starving them of light, and that depth is the deal-breaker – a thin layer just gives seeds a nice seedbed. Established perennial weeds like bindweed will come through any mulch; those need dealing with before you lay it.

Can I put wood chips straight onto a border?

Wood chips can go straight onto weeded, moist soil in a planted border, and that is exactly how I lay them. The one preparation that matters is clearing perennial weeds first – the mulch suppresses what tries to germinate afterwards, not what is already rooted.

Do wood chips take nitrogen out of the soil?

Wood chips used as a surface mulch borrow very little nitrogen from established plants – the effect people worry about mainly happens when fresh wood is dug into the soil, where the microbes breaking it down strip nitrogen as they work. Keep chips on the surface and keep fresh chips away from young plants, and it is rarely a problem worth losing sleep over.

Should I use wood chip or bark for a play area?

For a play area the certification matters more than the material: either is fine if it is tested to BS EN 1177 and laid at the depth the fall height demands, and neither is safe if it is garden-grade. Between the two certified options, hardwood play chip lasts longer and softwood is a little cheaper and softer.

Are wood chips and mulch the same thing?

Wood chips are one kind of mulch, not a synonym for it – mulch is anything laid on the soil surface to protect it, from bark and compost to gravel. The full family tree is in my what is mulch guide.