Mowing Tall Grass, Pastures, Paddocks and Fields With A Zero-Turn Mower

I just got an email from Home Depot this morning. It stated, “Our Riding Mowers are Ready to Take on the Toughest Yard.”  Little do they know what that really means.

Many of you want to mow Tall Grass, Pastures, Paddocks, and Fields With A Zero-Turn Mower. The mower manufactures all assume you have enough common sense not to mow tall grass and brush out in the horse pasture, but I know that many of you will try it anyway. Well, I have a little experience I’ll give you about mowing those types properties so that you can mow them and not wreck your lawn mower.

My Experience:

One of the mowing contracts I had, was to mow around electrical sub-stations, cooling canals and power plants for the electric utility company in Northern Illinois. There were 300 properties to mow. These properties ranged from areas the size of your garage to over 40 acres. Some of the in-town properties were mowed once a week. Others, on the edge of town, were mowed twice a month, and some in the rural areas were mowed once a month.

Northern Illinois has some of the richest black dirt in the world so once a month mowing meant the grass was usually around 24 inches tall but the weeds could easily grow 4 feet or higher.

The rural properties that were contracted for once a month ranged from 1/4 acres to a little over 40 acres. In addition, there were two monthly properties where I had to mow a 12-foot wide path or roadway on the top of levees around the power plant cooling lakes. From the distance cooling lakes look like one large lake but in reality, they are one long series of canals that wrap back and forth. The tops of these canal berms didn’t have paved roads, just gravel, and a little dirt that over the years collected weeds and a little grass. Being in such close proximity to the warm water of the cooling lake the weeds thrived and could easily get 6 to 10 feet tall if not mowed down once in a while. The utility company personnel and Department of Natural Resources periodically went out and inspected the canals so they wanted tops of the canal berms maintained well enough so the weeds wouldn’t get wrapped around the driveshafts of the trucks and short enough so they could see where they were going on the curves. The water area of the lakes totaled around 3900 acres but the length of the roadways I had to mow totaled 27 miles!

I was too inexperienced and too cheap to buy a bush-hog/tractor plus a truck and trailer large enough to haul it so I used commercial zero-turns for the first 2 years. I learned a lot about what a zero-turn could and couldn’t do mowing tall grass and weeds.

How To Mow Long Grass and Weeds.

Zero-turn mowers are designed to mow lawns. Almost all of them today will give you golf course finish if you mow once a week and don’t let the grass get more than 6 inches tall. The process I’ll state here is mainly for high end residential and commercial ZTR’s with fabricated decks and cast iron spindle housings. Your $2500-$4000 zero-turn will be quickly destroyed if you try to mow tall grass and weeds.

If the grass is taller than the frame of the mower you can get the job done if you follow these suggestions.

Warnings First:

1.If at all possible go out in the spring before the grass starts to grow and walk the entire area inspecting it for rocks, debris, potholes, and gulleys. Do this every year and preferably every time you mow. Pick up the debris, pick up sticks larger than your thumb, dig up the rocks and mark the mounds and ditches that can break your mower. ZTRs have stiff frames so it’s actually very easy to get a ZTR stuck in a rut, pothole or soft spot.

2, Pick up all plastic trash. Plastic grocery bags are notorious for wrapping around your mower deck spindles so tight that they will break the deck belt or cut the grease seal on the spindle bearings.

Kut Kwick Super SlopeMaster ZTR

3. Not one of the zero-turn mowers on the market under $25,000 are designed to cut brush. If you don’t want to wreck your mower, any woody plants like the oak and pines bigger than your thumb need to be cut off at ground level before you mow the area. The spindles on your mower are not designed to take the shock of cutting brush. You will bust aluminum spindle housings and ruin the ball bearings in cast iron housings if you try to cut brush larger than the size of your thumb.

4. Not one of the zero-turn mowers on the market today under $25,000 are designed to cut weeds and grass taller than the frame of the mower.  It’s possible to damage your mower deck, belts and PTO clutch by grass wrapping around the spindles, the engine by too much debris or the transmissions by over-heating pushing over tough weeds. Grass will wrap around the spindles underneath the mower deck and cut the grease seals on the bearings.

Now – Raise the deck up all the way.

• When you mow the tall weeds the mower will just knock them down and will not mow all of it off on the first pass. Go in one direction and then turn around and mow over it again in the opposite direction. You may have to do this two or three times before it mows it off cleanly. You may find that instead of turning around backing up for the second pass may cut it faster. Yes, a two-acre paddock will take a long time.
• Go slow – at a walking pace on the first pass. This will give the wildlife a chance to get away and will help to keep from overworking your mower.
• If you smell burning rubber at any time – Stop the mower. Turn the mower completely off, remove the key, set the parking brake and look under the deck. Grass will be wrapped around the spindles. Cut it off with a utility knife.
• Every 30 minutes or so stop the mower. Turn it off completely, remove the key, set the parking brake and look under the deck. If there is a lot of grass wrapped around the spindles cut it off. A sharp utility knife works very well.
• Check your engine cooling especially if it’s dry and there is a lot of dust in the air. If there is grass and debris on the top of the engine – clean it off. Clean around the engine and remove most of the dead grass that is collecting under the seat and around the engine. The dry grass under the seat can overheat the electrical wires and cause a fire. Use gloves because a lot of weeds will have prickly spines and edges. A leaf blower works well to blow this stuff off.  If you have an auxiliary oil cooler check the fins of the cooler for debris. Also, blow off the top of the deck.
• Touch the blade spindles with your fingers. If the housing is too hot to leave your finger on it more than a couple of seconds you have a lubrication issue. Grease the spindle (top and bottom if so equipped) if it is cast iron. If it is aluminum you have a bearing going out. Stop and repair it before you do more damage.
• When you are done, especially if the grass has a lot of moisture in it the deck will be full of grass underneath. Clean that out with a putty knife, old board, or even a kitchen spatula. Cut the long grass and weeds wrapped around the spindles. I suggest removing the mower blades. That makes it easier to get the grass off the spindles. Pay attention to the area right above the blades to make sure grass is removed from the grease seal.
• If the grass is really dry there will be a lot of clippings on top of the deck. Clean that off with your hands and then blow the rest off. Get behind and under the belt covers. Don’t use a pressure washer – it just makes a mess and will force water into the spindle bearings.
• One last thing, If you feel safe to do this and there will be no one else in the area, tie the discharge cover up two inches or so with a rope or bungee cord. This will help the deck clear the grass faster. Remember, your blades spin at the tips 18,500 feet per minute. With that cover raised up your deck can throw a baseball-sized rock, a piece of wood or other debris 600 feet or more.
• One of the big issues of using a zero-turn on long grass is traction – especially if the ground underneath is water saturated. What I mean is most of the time the type grasses that grow in the fields are clumping grass – the grass grows in mounds and there is little or no vegetation between the mounds. These bare spots will be wet and will cause a zero-turn to get stuck. Zero-turns have very little traction because of the stiff frame.
• Traction is even more of a safety issue if the grass is dry. The long dry grass is very slippery and you can easily slide down a slope and tip the ZTR over. Late summer is always a bad time to mow long grass on any type of slope.
• Another big issue with clumping grasses and zero-turns is the grass mound itself can be so dense that when you go over it the mower does not have enough traction to push the mower deck past the mound and the zero-turn gets stuck on the clump of grass. I’ve seen this happen a lot with the midwestern prairie grasses. You can’t get the deck high enough to mow over the prairie grass mounds. Because of that you may not be able to mow all of your wildlife prairies.

Feel free to add any other suggestions in the comment section below.

Be Safe, If you can buy, rent, borrow, hire a bush hog style tractor-mower, pull behind rough cut mower or a walk-behind made for tall grass instead of beating up your ZTR.

Remember, it’s not the mower’s or the manufacturer’s fault if the ZTR breaks when trying to mow tall grass. Repairs won’t be covered under warranty.