Burrs in wool are spiny seed pods and plant debris that tangle into fleece and raise costs at every processing step.
Shearers, spinners, and mills all meet the same headache: plant seeds with hooks that hitch a ride on fibre. If you came wondering what are burrs in wool, this guide explains what they are, how they get there, why mills charge more for burry clips, and the practical steps that keep fleeces clean.
What Are Burrs In Wool? Types, Damage, Fixes
Burrs are a subset of vegetable matter — the catch-all term for seeds, burrs, grass, shive, and similar fragments in greasy fleece. The worst offenders are hooked or barbed seed heads that lock into staples, ride through scouring, and snag machinery. Heavy burr loads lower yield, push wool into harsher treatments, and can even write off a spinning lot.
Common Burr Plants You’ll Hear About
Different regions have different problem plants, but their effect on fleece is the same: tangles, skin irritation, and lower sale value. Here’s a quick field guide you can skim before turnout or purchase.
| Plant Or Burr | Where It Thrives | Traits That Catch Wool |
|---|---|---|
| Noogoora burr (cocklebur) | Warm river flats, disturbed soils | Oval, spined pods; cling hard; often needs carbonising |
| Bathurst burr | Semi-arid rangelands | Tri-spined burrs; embed in belly wool and neck |
| Burdock | Road edges, damp gullies | Hooked bracts; form mats in long staples |
| Khaki weed | Yards, laneways, stock camps | Small, hard burrs; spread by feet and fleece |
| Cleavers (sticky weed) | Shady paddocks, fences | Velcro-like surface; seeds ride deep into fleece |
| Three-cornered jack (caltrop) | Hot, sandy ground | Spiky nutlets; painful to stock; hard on skirting tables |
| Wild carrot/Queen Anne’s lace | Dry pastures | Dry umbels break up; fine chaff lodges through staples |
| Storksbill/filaree | Mediterranean climates | Corkscrew awns; work down to the skin |
Noogoora burr is a classic example of a wool spoiler. In many districts those pods mat fleece on the neck and belly and can force mills to use carbonising. Read the weed note from Agriculture Victoria on Noogoora burr for a sense of how hard these seeds hang on.
Why Burrs Cost You Money
Burr seeds add weight but not fibre. Test houses report a higher vegetable matter percentage, which lowers clean yield and buyers discount the clip. Some burrs can be shaken or combed away in opening and carding, but stubborn spiny pods often go to carbonising — an acid treatment that burns out plant material and adds cost while changing handle.
Burrs In Wool Meaning And Why They Matter
In auction language you’ll see “VM” to report vegetable matter content by weight. A low VM% improves mill efficiency and fabric quality. A high VM% warns of extra waste and more aggressive cleaning. The phrase what are burrs in wool shows up whenever spinners suspect seeds will survive scouring and show up as neps, pills, or prickles in yarn.
Where Burrs Hide On A Fleece
Bellies, points, and the neck pick up the most seeds. Breech wool is often hairy and traps spines. Along the back, open fleece lets awns fall in. Skirting removes these zones before sale so the main line shows the true quality of the mid-side.
How Burrs Travel From Paddock To Cone
Seeds mature, dry, and grab any passing coat. Sheep brush against plants in gateways or watercourses, the burrs lock onto the staple tips, and movement drives them deeper. If shearing runs late in a seedy season, fresh burrs jump straight into the shed. From there they ride through bags, presses, scours, cards, and combs unless you intercept them.
Prevention On Farm: Small Habits, Big Wins
You don’t need an herbicide program to make progress. Start with paddock choice when seeds set, draft the cleanest mobs to clean paddocks, and bring stock off burr-heavy blocks before seed drop. Time shearing to miss the worst seed shed in your district. In yards, keep laneways slashed and avoid hay bedding near shearing.
Stock And Genetics
Dense, well-crimped fleeces shed dust better than open, hairy coats. Selection for staple structure and belly coverage pays off in VM% over time. Rams bred in clean country often carry tighter fleeces that resist seed penetration.
Shed Workflow That Knocks VM Down
Good shed flow saves your classer from fighting burrs later. Shake out fleeces on a mesh table, keep separate bins for bellies and locks, and skirt hard around stained or burry edges. Bag burry lines so they don’t seed the rest of the clip while pressed.
Processing Reality: What Mills Can And Can’t Remove
Opening and carding remove loose straw and chaff. Combing rejects short, contaminated fibres. Spiny burr pods resist these steps, so mills turn to carbonising. That treatment works well on plant bits that refuse to break apart, but it adds expense and can dull the natural bounce of apparel wool. That’s why buyers pay more for clean clips in the first place.
Spinner’s View: Why Burrs Feel Worse Than They Look
Hand spinners know the pain: picking out burrs takes time and the little ones still scratch fingers. Nubs from broken seeds make thick-and-thin drafting and leave peppery specks after dyeing. Many fibre artists pass on a fleece if the neck or breech shows heavy vegetable matter, even when the micron is lovely.
Simple Tests To Gauge Burr Trouble
Grab a staple from mid-side, hold the tip down, and tap: loose chaff falls. Bend the staple back on itself: if you hear crackle, there’s embedded seed. Draft a few tufts between fingertips: snagging hints at Velcro-like seeds. These quick checks help buyers avoid surprises at the wheel or in the mill.
Seasonal Timing And Regional Clues
Seed shed peaks vary by climate. In hot inland zones, late summer brings fresh burrs; in cool temperate districts, early autumn can be riskier. River flats with flood-carried silt are perfect for cocklebur. High traffic laneways and holding yards grow khaki weed and cleavers that stick to legs and muzzles. Local notes from classers and agents beat broad calendars, so keep a seasonal log tied to your paddocks.
Skirting And Cleaning: Step-By-Step
Skirting is your first and cheapest filter. Roll the fleece flesh-side in, throw it on the table cut-side down, and walk the edge. Off come dags, stained pieces, short points, and every obvious burr patch. If the fleece came from seedy country, split off a separate “burry” line so the main fleece sells clean.
Targeted Picks Before Washing
Pick what you can see while the grease still holds structure. Use blunt tweezers on cockleburs, flick cleavers away with a dog comb, and tease out mats with a flick carder. Shake, flip, and shake again so fines fall through the grate.
Wash, Then Mechanical Removal
After scouring and drying, short VM that survived grease can be carded out. Two or three gentle passes often free trapped bits without breaking staples. For worsted prep, combing removes a stream of short fibres carrying seeds, leaving a long, clean top ready for spinning.
When Carbonising Makes Sense
Some burr pods refuse to budge. Mills may choose an acid bath to destroy plant matter and save the lot. It’s common on crossbred apparel types when seed levels are high. Expect extra handling fees and a flatter, whiter look versus non-carbonised wool.
Removal Methods Compared
The best method depends on seed type, fibre length, and volume. Use this at-a-glance guide to choose your next step.
| Method | Best Use | Trade-Offs |
|---|---|---|
| Hard skirting | Obvious burr patches, bellies, points | Reduces weight; boosts sale value; losses acceptable |
| Hand picking | Large burr pods in small lots | Slow; misses fines; good for premium handspinning lines |
| Dog/flick combing | Velcro-type seeds in tips | Can break tips if rushed; helps before carding |
| Carding | Short VM and chaff | Multiple passes needed; may create neps if aggressive |
| Combing | Long fibres headed to worsted | Throws out short fibre; lowers yield but cleans top |
| Carbonising | Stubborn spiny pods; big lots | Extra cost; changes handle and colour |
| Paddock control | Next season’s fleece | Planning and timing; best long-term payoff |
Buying Raw Fleeces: VM Clues In Photos
Ask sellers for clear shots of the neck, breech, and cut face. Look for peppered tips and matted patches along the edges. Clean mid-side with bright, even crimp suggests an easier skirt. If a fleece shows heavy seed in the neck, bid as if you’ll lose that section on the table.
Glossary: VM Words You’ll See
Vegetable Matter (VM)
All plant-based contamination in wool by weight: seeds, burrs, shive, and similar fragments.
Burry
A classer’s note that burr pods are present. Expect extra skirting and possible carbonising.
Carbonising
Chemical removal of stubborn plant material. Effective on spiny burrs that won’t card or comb out.
Skirting
Trimming contaminated, short, or stained edges to protect the main line of the fleece.
What Buyers Mean By “VM%” And “Burry”
Test reports list vegetable matter by weight. Low numbers help apparel mills, raise confidence, and keep clips out of carbonising lines. Catalog notes like “burry neck” or “seedy bellies” alert you to likely waste in skirting. For private fleece sales, sellers often share raw photos of the skirting pile so buyers see what stayed out of the bag.
Quick Answers To Common Situations
Can You Spin A Burry Fleece?
Yes, with patience. Make a lighter yarn from the clean mid-side and save the burry edge for textured batts or felting where a few specks won’t hurt.
Does Washing Remove Burrs?
Grease can mask seeds. Washing helps fines fall out, but spiny pods grip tighter once the lanolin is gone. Pick before and after scouring.
Will Burrs Hurt Sheep?
Heavy seed heads can rub skin raw, lodge in eyes or feet, and slow grazing. Moving flocks off weedy blocks before seeds set keeps stock comfortable and wool clean.
Bringing It Together
If you’re buying or growing fleece, the phrase what are burrs in wool sits at the start of every good clip. Burrs are barbed seeds and plant bits that ride into staples, lower yield, and force mills into costly treatments. Clean paddocks, smart shearing dates, disciplined skirting, and right-sized processing choices turn a scratchy, seedy headache into smooth, mill-ready fibre.