Quick answer: A plain disc mower just cuts; a mower-conditioner (MoCo, discbine, or older sickle-bar haybine) cuts and crimps or scuffs the stem to speed drying. Buy a disc mower if you make mostly grass hay or baleage, dry in good weather, or want the cheapest, simplest, lowest-horsepower option — a used 9-foot disc mower runs a fraction of a comparable MoCo. Buy a mower-conditioner if you make real dry hay, especially in humid or cool climates, where conditioning routinely buys you a half-day to a full day of dry-down. Climate and crop drive the decision more than brand.
"Do I need a conditioner, or will a plain disc mower do?" is one of the most-argued questions in haymaking — and the honest answer is that it depends on your weather, your crop, and your budget, not on which color iron you like. We pulled together the real-world experience hay producers shared on the forums, lined it up against the agronomy, and turned it into a straight buying guide. Here's how to choose.
Disc mower vs. mower-conditioner: what's actually different?
All of these machines cut the crop. The difference is what happens to the stem after the blade:
- Disc mower — spinning discs cut the crop and lay it down. That's it. No stem treatment. Lightest, cheapest, lowest horsepower, fewest moving parts.
- Mower-conditioner (MoCo / discbine) — discs cut, then the crop passes through conditioning rolls (which crimp the stem) or an impeller/flail (which scuffs the waxy stem surface). Cracking the stem lets trapped moisture escape, speeding the slow final dry-down.
- Haybine — the older sickle-bar mower-conditioner. Most producers who've switched won't go back to a sickle cutterbar. As one put it:
"You said used haybine, I assume you meant discbine — you couldn't give me a haybine anymore but you couldn't buy my discbine from me."
— Hayman1 · HayTalk thread 23039
So the core buying question isn't really "what brand" — it's "do I pay for the conditioner, or not?" The rest of this guide answers that, then covers the cutterbar and machine details that matter once you've decided.
The case for a plain disc mower
A disc mower wins on price, simplicity, and horsepower. If your hay is mostly fine-stemmed grass — or you're wrapping baleage and only need to wilt the crop — you may simply not need to crimp the stem at all.
"If you are just mowing grasses and don't really need to crimp stems, you would be fine running a disc mower. That's what I'm doing. Heck of a lot cheaper too."
— Hawkins2015 · HayTalk thread 100357
He pegs a decent used 9-foot 3-point disc mower at "around 5–6k" — a fraction of what a comparable mower-conditioner costs new or used. The savings compound when you pair a disc mower with a tedder instead of buying a MoCo:
"If you're doing pretty much all grass hay the mower-tedder works good, saves the expense and maintenance of a conditioner... Let's say you were buying new, you can get a disc mower and a tedder before you can even touch a mower/conditioner. And brand doesn't matter. You also can do the mower and tedder with a smaller tractor or if you already have bigger ones it will use a lot less fuel."
— siscofarms · HayTalk thread 98260
This is the disc-mower-plus-tedder playbook, and in good drying weather it holds up. A producer in the humid Ohio Valley runs exactly that setup:
"I use a disc mower and a tedder. I run the tedder right behind the mower... I have good luck with this approach and make a lot of 3 day hay in the Ohio Valley. It's hot and humid and sucks for making dry hay."
— cjsr8595 · HayTalk thread 98260
And if you make baleage, the conditioner question gets even easier — unconditioned forage actually dries faster the first day, which is all wet wrapping needs. We dig into that in do you need a conditioner for baleage? One caveat with a plain disc mower: your rake has to gather a clean windrow behind it, since the crop isn't formed into a tidy swath. Match it carefully using our rake selection guide.
The case for a mower-conditioner
Conditioning earns its money on real dry hay — the last, slow 20% of moisture — and the further north and more humid you are, the more it matters. Plenty of experienced producers consider it non-negotiable:
"I wouldn't even consider a mower with no conditioner. I'd quit baling hay before I'd go away from a conditioner. If you need more than what a conditioner can do, then add the tedder."
— Gearclash · HayTalk thread 98260
In cool, damp country the dry-down gap is measurable, and a moisture monitor settles the argument:
"I have 2 mowers, one with conditioners and one without. In the same field mowed the same day the unconditioned hay is always at least 1 day behind and sometimes 2 up here in the cool, damp north country."
— chevytaHOE5674 · HayTalk thread 98260
It's not unanimous, though — and that's the useful part. One producer in a wet, humid area ran both side by side and found the conditioner didn't save him a tedder pass:
"I used to say the same thing as I'm in a very wet humid area. Then I tried without. The conditioner did not save me a tedder pass. Very little difference in time of day I can start to bale on day 2 or 3... Note this is all in grass hay."
— slowzuki · HayTalk thread 98260
The takeaway: in grass hay with decent drying, a tedder can do much of what a conditioner does. In legume hay (alfalfa, clover) and in marginal weather, the conditioner pulls ahead. If you do buy a MoCo, the next decision is rolls vs. impeller — and it splits cleanly by crop. We cover that choice in full in the rolls vs. impeller conditioner guide; the short version is rolls/crimp for thick-stemmed seed crops, impeller/flail for alfalfa and grass.
Let climate and crop pick for you
Strip away the brand loyalty and the decision comes down to two questions: how reliably does your hay dry, and what are you cutting? This is the cheat sheet that emerges from the threads:
| Your situation | Lean toward | Why |
|---|---|---|
| Mostly baleage / wet wrapping | Disc mower | You only wilt to 50–60%; unconditioned dries faster the first day |
| Grass hay, good drying weather | Disc mower + tedder | Cheaper, less HP, and a tedder closes most of the dry-down gap |
| Dry hay in humid or cool climates | Mower-conditioner | Conditioning routinely buys a half-day to full day of dry-down |
| Alfalfa and other legumes for dry hay | Mower-conditioner | Crimping/scuffing the waxy stem speeds the slow final drying |
| Rocky ground, lots of debris | Disc mower | Fewer parts to damage; conditioning rolls add risk and cost |
Whichever way you lean, a tedder is the great equalizer — most producers run one regardless. If dry-down speed is your real goal, read how to make dry hay faster and our hay tedder guide before you spend on a conditioner you may not need.
Before you buy: 6 things that matter more than brand
Once you've settled the conditioner question, these are the details that separate a machine you'll keep for 15 years from one that frustrates you every season.
- Shaft-drive vs. belt-drive disc cutterbar. A shaft-driven cutterbar handles tough, stemmy grasses that can stall a belt-driven one: "My Krone is shaft drive. It will cut tough grasses such as Love grass where belt drive disc cutter wouldn't," notes Tx Jim in thread 100357. If you cut rank or coarse grass, prioritize it.
- Skid shoes and scalping. More skid shoes across the bar means less scalping on uneven ground. As Grateful11 explains, "each cutter... has a skid shoe, so it has 7 skid shoes. If there's a slight high spot in the center of the cutterbar it doesn't scalp the ground." A bar with shoes only on the ends will gouge a crowned field.
- Transport height. A folded 9- or 10-foot disc mower on a trailered tractor can exceed legal non-permit height and tear down wires. "One big issue is a 10' cut disc mower attached to a tractor sitting on a deck-over trailer is taller than the non-permit limit," warns dvcochran. Measure before you haul.
- Dealer support and parts. The single most-repeated piece of advice: buy the color your local dealer stocks parts for. "A lot depends on dealer support and parts availability. I run NH because I have three dealers within an hour," says mlappin. A cheaper machine you can't get blades for in July is no bargain.
- Durability and maintenance. Trailed mower-conditioners with a fully suspended cutterbar tend to last; heavy conditioning rolls add bearing wear. One producer ran a John Deere MoCo 17 years and "never touched the cutterbar in all that time." Ask what wears.
- Buy your baler first. If money is tight, prioritize the baler over the mower: "If you have the best mower and your baler breaks you lose lots of money potentially. But if mower breaks, hay still standing degrades much more slowly than hay on the ground," reasons deadmoose.
The bottom line
- Mostly grass hay or baleage, decent weather? A plain disc mower (plus a tedder) is cheaper, simpler, and usually enough.
- Real dry hay, especially humid or cool climates or legumes? Buy the mower-conditioner — the dry-down gap is real.
- Running a conditioner? Choose rolls vs. impeller by crop, not habit.
- Either way, weight your decision toward shaft drive (for tough grass), good skid-shoe coverage, manageable transport height, and a dealer who actually stocks parts.
However you cut it, finish the job with a tight bale and good net wrap — and if you're moving into wet wrapping, start with our first-time baleage guide.
Frequently asked questions
Do I need a mower-conditioner, or is a disc mower enough?
It depends on your crop and climate. If you make mostly grass hay or baleage and dry in good weather, a plain disc mower — often paired with a tedder — is cheaper, simpler, and usually enough. If you make real dry hay, especially alfalfa or in humid or cool climates, a mower-conditioner typically buys you a half-day to a full day of faster dry-down, which is worth the extra cost and horsepower.
What is the difference between a haybine, a discbine, and a mower-conditioner?
"Mower-conditioner" is the general term for a machine that cuts and then crimps or scuffs the stem. A haybine is the older sickle-bar version; a discbine is the modern disc-cutterbar version. Most producers who have switched strongly prefer a disc cutterbar over a sickle bar for speed, reliability, and the ability to power through tough or down crop without plugging.
Is a disc mower cheaper than a mower-conditioner?
Yes, considerably. A disc mower has no conditioning rolls or impeller, so it is lighter, simpler, needs less horsepower, and costs much less to buy and maintain. Forum producers find decent used 9-foot disc mowers for a fraction of a comparable mower-conditioner, and note you can buy a disc mower plus a tedder for less than a single MoCo.
Does a disc mower without a conditioner make hay dry slower?
Often slightly, but not always enough to matter. In humid or cool climates, conditioned hay can be a half-day to a full day ahead. In grass hay with good drying weather, a tedder run right behind the mower closes most of that gap. For baleage, unconditioned forage actually dries faster the first day, so a disc mower is the better, cheaper choice.
Should I worry about rocks with a mower-conditioner?
Rocky, debris-filled ground is one of the better reasons to favor a plain disc mower, which has fewer vulnerable parts than conditioning rolls. If you run a mower-conditioner on stony ground, look for shear protection (sacrificial rotors or shear pins), a higher stubble-height kit, and good skid-shoe coverage, and clear surface rocks before they wreck a cutterbar.
The XES Netting team manufactures bale net wrap for round balers and writes these guides so forage operators can find clear, source-cited answers. Every farmer quote in this post is verbatim with a link to the original HayTalk thread — go read the discussions in full.
Featured photo: JF GX 2400 SM mower with conditioner by Christer Folkesson, licensed under CC BY 3.0, via Wikimedia Commons.
