# mowing the lawn - spiral vs. boustrophedon **URL:** \ **Category:** Factual Questions\ **Created:** [September 23, 2003, 1:05am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216 "2003-09-23T01:05:27Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![aesop](https://avatars.discourse-cdn.com/v4/letter/a/5f8ce5/32.png) [@aesop](https://boards.straightdope.com/u/aesop)\ **Post date:** [September 23, 2003, 1:05am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/1 "2003-09-23T01:05:27Z")
I need help from the mathematically inclined… I always used to mow my lawn in spiral fashion (albeit a squared-off spiral) – that is, mowing along the outside edge first and then just inside the first cut on the next pass, then just inside the 2nd cut on the 3rd pass, etc. Recently however I have begun to mow boustrophedon – a simple back and forth pattern. And I seem to be finishing MUCH more quickly. So I’m wondering, is it really noticeably shorter to mow back & forth vs. spirally? Does the spiral travel path add that much more distance? Can someone work out an example for me – assuming I have a rectangular lawn that is 50’ by 100’, and a mower with a 2’ deck, and that there is no overlap on each cut, the boustrophedon path will be 25 x 100’ = 2500 feet, right? So how far will I have to travel to mow the lawn in spiral fashion? P.S. if the math is easier with other numbers, please substitute. And as you may have guessed, I was always lousy at calculus. ---
**Author:** ![Not\_In\_Anger](https://avatars.discourse-cdn.com/v4/letter/n/3ab097/32.png) [@Not\_In\_Anger](https://boards.straightdope.com/u/Not_In_Anger)\ **Post date:** [September 23, 2003, 1:25am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/2 "2003-09-23T01:25:27Z")
Spiralling is weird. I mow boustrophedon, with the modification that I mow a line first forward, then retrace the line backwards. Not that that speeds up the process, but it catches the grass that was trying to escape by bending over in the direction you originally headed. I’m smarter than grass. A slight hijack. I have certain neighbours who mow diagionally, then mow perpendicular to that, so it forms a cross-patch pattern. I consider that anal. Am I right, or not right? ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [September 23, 2003, 1:29am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/3 "2003-09-23T01:29:12Z")
Assuming you’re traveling the same speed in both cases, and the “overlap” you refer to in the spiral case is similar to the overlap you’d allow going back and forth… it should take exactly the same amount of time. You say you _seem_ to be finishing quicker. Can you check it with some stopwatch style precision? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [September 23, 2003, 1:30am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/4 "2003-09-23T01:30:42Z")
Forget the distance, the number of turns alone will slow you down appreciably. Every time you turn, you stop momentarily. When you mow in a line you make one turn at the end of every row. That’s effectively 2 turns to mow 300’, one at the end of the first row and one at the end of the second. When you mow in spiral you move 100’, turn, move 50’, turn, move 100’, turn, move 50’. That’s 3 turns for every 300’. As the remaining area gets smaller the discrepancy gets larger. Even on the last runs in a straight line pattern you still only make 2 turns ever 300’. With a spiral you might be making 10 or 20 turns to mow 100’. ---
**Author:** ![Not\_In\_Anger](https://avatars.discourse-cdn.com/v4/letter/n/3ab097/32.png) [@Not\_In\_Anger](https://boards.straightdope.com/u/Not_In_Anger)\ **Post date:** [September 23, 2003, 1:34am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/5 "2003-09-23T01:34:44Z")
Yeah, what he said. To spiral squarely, you have to turn the lawn mower. That takes time. ---
**Author:** ![Rabid\_Squirrel](https://avatars.discourse-cdn.com/v4/letter/r/e0b2c6/32.png) [@Rabid\_Squirrel](https://boards.straightdope.com/u/Rabid_Squirrel)\ **Post date:** [September 23, 2003, 1:44am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/6 "2003-09-23T01:44:18Z")
Rough estimate: - Assume perfectly square corners & no overlap - Use middle dimensions for the rectangle for each ‘circuit’. That means the mower starts out 1’ away from the edge of the lawn. For the first circuit, the mower travels 49’+(99-2_2’)’+49’+(99-2_2’). Note that I’m taking into account the corners. The next circuit would be 45’ + (95-2_2)’ + 45’ + (95-2_2)’, and so on. Bunging the whole lot into Excel gives this badly formatted list: [Length of circuit] [Width of circuit] [Length Travelled]49 99 288 45 95 280 41 91 264 37 87 248 33 83 232 29 79 216 25 75 200 21 71 184 17 67 168 13 63 152 9 59 136 5 55 120 1 51 52 \<==Wasted mowing TOTAL 2540 So the difference is slight. Most of the time would be wasted remowing sections, since it’s difficult to keep the mower in a perfect spiral. ---
**Author:** ![aesop](https://avatars.discourse-cdn.com/v4/letter/a/5f8ce5/32.png) [@aesop](https://boards.straightdope.com/u/aesop)\ **Post date:** [September 23, 2003, 2:11am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/7 "2003-09-23T02:11:26Z")
thanks Rabid Squirrel, for working out the math. Looks like Blake has it right – I hadn’t even considered the amount of extra time for turning. And as you pointed out, it’s not just the turns – lining up the next cut is more complicated in the spiral than in the back-and-forth. Not In Anger, you are right, the way your neighbors cut their grass is anal! ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [September 23, 2003, 2:36am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/8 "2003-09-23T02:36:30Z")
Alternate cutting patterns to prevent compaction. ---
**Author:** ![CnoteChris](https://avatars.discourse-cdn.com/v4/letter/c/278dde/32.png) [@CnoteChris](https://boards.straightdope.com/u/CnoteChris)\ **Post date:** [September 23, 2003, 2:40am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/9 "2003-09-23T02:40:08Z")
> [@](#): > > \*Originally posted by Philster \* > \*\*Alternate cutting patterns to prevent compaction. \*\* Me too. And that ain’t anal. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 23, 2003, 2:46am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/10 "2003-09-23T02:46:30Z")
There is a wonderful apocryphal story about the American tourist who was visiting Oxford and exclaiming over the perfection of the lawns there. Finding a groundskeeper out with a lawn mower the tourist asked how they kept the grass so beautiful. And the groundskeeper said, “You mow north-south for 200 years and then you mow east-west for 200 years.” ---
**Author:** ![Dogface](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dogface](https://boards.straightdope.com/u/Dogface)\ **Post date:** [September 23, 2003, 3:22am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/11 "2003-09-23T03:22:41Z")
Some lawn mower manuals come with instructions that specify to alternate boustrophedon. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [September 23, 2003, 7:47am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/12 "2003-09-23T07:47:14Z")
Thanks to **aesop** for using the word boustrophedon! I was trying to remember it a while ago and it wouldn’t come up at all! [/hijack] ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [September 23, 2003, 10:45am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/13 "2003-09-23T10:45:21Z")
- - - With rotary-type mowers, you generally have to mow one direction, and then make another pass perpendicular to cut the grass really even. That’s the reason that commercial lawn services mow business parks that way–the second time hardly takes any fuel, but evens out the grass height a lot… _Spool-type_ power mowers can get it perfect on the first pass, but they cost lots more money. ~ ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [September 23, 2003, 11:54am UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/14 "2003-09-23T11:54:20Z")
You just wanted an excuse to drop “boustrophedon” into the conversation, you sad dictionary-swallower you! (I ought to be fooling around with [font=symbol] or something, but life’s too short.) Still, with a name like **aesop** , I guess you can be forgiven 🆒 ---
**Author:** ![j.c](https://avatars.discourse-cdn.com/v4/letter/j/73ab20/32.png) [@j.c](https://boards.straightdope.com/u/j.c)\ **Post date:** [September 23, 2003, 6:35pm UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/15 "2003-09-23T18:35:48Z")
I have a mulching mower, which means the mower needs to go back over piles of grass at least once and all the grass needs to blown to the inside of the section of lawn being mowed so that it’s in one place to be “mulched” and doesn’t blow all over the sidewalk or the deck or the neighbor’s yard. But you bag people and leaf-blower people may not care about such things… ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [September 23, 2003, 8:31pm UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/16 "2003-09-23T20:31:23Z")
My empirical experience is different than the theorists above posit. I used to mow back & forth, then switched to a decreasing spiral, starting around the perimeter of my yard working in. I cut my mowing time from 50 minutes to 40 minutes very consistently. In rebuttal to **Blake’s** theory > [@](#): > > Every time you turn, you stop momentarily. . . .When you mow in spiral you move 100’, turn, move 50’, turn. . . . When you mow in a spiral you’re only turning 90 degrees, not 180, so you don’t have to stop at all (God forbid you would have to stop your car every time you turn a corner). In boustophedon (new word for me) you have to completely stop, if only briefly. My spiral rounds off after a couple of passes, I don’t try to keep it square, and that speeds up the turns. Keeping it utterly square would cause you to lose a little time in the turn. The most time-consuming was when I mowed back & forth on a diagonal, and alternated the slant from cut to cut. Forget that crap unless your competing with neighbors. ---
**Author:** ![Zyada](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zyada/32/3028_2.png) [@Zyada](https://boards.straightdope.com/u/Zyada)\ **Post date:** [October 1, 2003, 3:11pm UTC](https://boards.straightdope.com/t/mowing-the-lawn-spiral-vs-boustrophedon/203216/17 "2003-10-01T15:11:30Z")
Back before I got lazy and hired a lawn service, I would mow in a decreasing spiral with the blower facing out. (Except for the first circle, which by necessity pointed inward). This distributed the grass clippings very evenly across the yard. Thus I avoided the necessity of raking and bagging the clippings - which saved a \lot\ of time and the part of mowing I hated.