As you mow with any mower, zero turn or not, you’ll have to overlap each pass at least a little to avoid leaving a thin strip of uncut grass. The traditional rule of thumb is that you should sacrifice 10% of your mowing width in order to ensure that you don’t leave any uncut strips. (example: 6″ overlap for 60″ deck) Other people say that 3 inches of ovelap is best, regardless of the width of your mower.
But don’t you want to take full advantage of your mower width? Lawn mowers get quite expensive the wider they are. Isn’t it a shame to pay so much for a mower and then not utilize all of what you have? Yes some overlap is necessary, but I want to minimize the overlap. But how do you do that? After all the effective width of your mower directly impacts the amount of time it takes to mow a yard. (and the cost to mow a yard).
The simplest method is to mark a spot on your mower deck with a pen or temporary tape. The mark should be approximately at the edge of your blade – the widest extent that the tip of the blade reaches. It’s going to be hard to tell exactly where this mark is since you cant see exactly how close the tip of the blade gets to the edge of the deck – but just estimate. See picture below.
Next a little experimenting will be required. Mow a lap, trying your hardest to line up the line of uncut grass with the mark you made on your deck.
If you left a strip of uncut grass, then you need to move your mark in towards the center of the deck (so that your mower blade will move outwards when you repeat your test lap.
If you didn’t leave a strip of uncut grass, move your deck mark outwards in 1 inch increments and make more test laps until you DO leave a strip of uncut grass.
Now move your mark back inwards on the deck by the width of the uncut grass plus you desired overlap amount (I think 2 inches is about right).
Finally, make the deck mark more permanent(ish) with some waterproof, outdoor tape like this kind.
Yes this process requires a bit of work, but you only have to do it once. Then you’ll be optimized for the rest of the season (and the rest of the lifetime for that mower).
If you try this technique for yourself I want to hear about it. Let me know how it worked for you in the comments.