# Dead patches in my grass **URL:** \ **Category:** Factual Questions\ **Created:** [May 23, 2008, 7:18pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401 "2008-05-23T19:18:02Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Belrix](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@Belrix](https://boards.straightdope.com/u/Belrix)\ **Post date:** [May 23, 2008, 7:18pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/1 "2008-05-23T19:18:02Z")
I mowed my backyard last week with my brand-new [electric mower](http://boards.straightdope.com/sdmb/showthread.php?t=464307). As I was mowing, the wheels kept dropping into these holes in the otherwise very dense grass. There’s spots where the grass doesn’t grow at all. No weeds, no other vegetation, just nothing in a circle the size of a coffee can. It’s like those spots in the “UFO Files” where the saucer landed and killed everything where the landing gear touched. The previous resident had a male dog if that means anything. Should I sod these spots? Dig them up and refill with potting soil? Just seed? Wait? It’s not a big appearance thing, really. I’m not that much of a lawn person, but they’re actually deep enough to grab the wheel of the mower and make mowing a jarring, annoying experience. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [May 23, 2008, 7:55pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/2 "2008-05-23T19:55:34Z")
Dig into them and make sure they are not old fence posts or something. Could be concrete or something else, because even though grass won’t grow there, it should have filled in with weeds. ---
**Author:** ![Daerlyn](https://avatars.discourse-cdn.com/v4/letter/d/898d66/32.png) [@Daerlyn](https://boards.straightdope.com/u/Daerlyn)\ **Post date:** [May 23, 2008, 7:59pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/3 "2008-05-23T19:59:41Z")
It is my understanding that dog urine in small amounts is good for grass, but in large amounts will kill it. Is the area around the dead spots particularly green? These may have been the dog’s favourite pee spots. ---
**Author:** ![The\_Them](https://avatars.discourse-cdn.com/v4/letter/t/898d66/32.png) [@The\_Them](https://boards.straightdope.com/u/The_Them)\ **Post date:** [May 24, 2008, 5:34am UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/4 "2008-05-24T05:34:10Z")
Dog pee, definitely. Good fertilizer, but “too much of a good thing…” The plant life got overstimulated with fixed nitrogen and croaked (so to speak). The spots will go away, but trowelling 'em up will make them go faster. Chuck some seeds in there when you do it. ---
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [May 24, 2008, 6:11am UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/5 "2008-05-24T06:11:43Z")
Gypsum. It cancels out the acidic pee. A good chunk of peet moss would be good to areate the soil too. Churn it up and mix in peet, gypsum, and grass seed. To a level higher than what you are working with, i.e. a mound. It settels and becomes flat pretty quickly. ---
**Author:** ![LiveOnAPlane](https://avatars.discourse-cdn.com/v4/letter/l/3d9bf3/32.png) [@LiveOnAPlane](https://boards.straightdope.com/u/LiveOnAPlane)\ **Post date:** [May 24, 2008, 2:35pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/6 "2008-05-24T14:35:17Z")
Both. As has been mentioned, you probably have an issue with dog pee, etc. Prep the lwan, and then I’d suggest sod for quicker results at this time of year. Some types of grass seed are slow to germinate, slow to grow, fill in/don’t fill in, and so on. Find a good grass type that works for your lawn and soil and climate. Lay down a good base of compost if your soil needs it (my ignorance on your soil here), and prep it well. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [May 24, 2008, 3:13pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/7 "2008-05-24T15:13:54Z")
I’m not so sure it’s dog pee, and not a fungus. A female dog will make spots like in the OP, but a male will go on things, not in the middle of the lawn (we’ve only had females, so fight my ignorance if necessary). But some lawn diseases will cause dead spots. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [May 24, 2008, 3:25pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/8 "2008-05-24T15:25:20Z")
Holes might mean only digging occurred. Dog pee isn’t permanent anyway, so you don’t need to get rid of any soil. Dig up the soil, and add enough that the holes are filled in, then seed it. Don’t make the mistake of using almost all annual grass. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 24, 2008, 7:29pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/9 "2008-05-24T19:29:33Z")
Could also be mushrooms. In my lawn, I have one spot, about the size of a coffee can with no grass or anything else. But about every other week all summer it fills in with gross slimey looking mushrooms. The rest of the time nothing grows there. ---
**Author:** ![USAEagle](https://avatars.discourse-cdn.com/v4/letter/u/7feea3/32.png) [@USAEagle](https://boards.straightdope.com/u/USAEagle)\ **Post date:** [May 25, 2008, 11:53am UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/10 "2008-05-25T11:53:02Z")
If you mix boiled rice into your dogs food, it reduces the acidity and won’t burn the lawn. Doesn’t have to be hot, or even fresh. My mother in law cooked enough for a week at a time. ---
**Author:** ![Digital\_Stimulus](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@Digital\_Stimulus](https://boards.straightdope.com/u/Digital_Stimulus)\ **Post date:** [May 25, 2008, 3:29pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/11 "2008-05-25T15:29:27Z")
[QUOTE=USAEagle] If you mix boiled rice into your dogs food, it reduces the acidity and won’t burn the lawn. Doesn’t have to be hot, or even fresh. My mother in law cooked enough for a week at a time. [/QUOTE] Cite? And I ask not as a challenge, but to verify something that might help our poor, spotty backyard before trying it. I had never heard this before, so I did some cursory googling. It seems that there’s a general consensus that it’s not the acidity of urine that damages a lawn, but the nitrogen content. I found people claiming both sides – some saying that adding rice will raise nitrogen levels, some saying lower. (Tomato juice was another suggested remedy.) I trust SDMB posts and references much more than arbitrary internet posts. So: cite? ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [May 25, 2008, 5:02pm UTC](https://boards.straightdope.com/t/dead-patches-in-my-grass/450401/12 "2008-05-25T17:02:00Z")
[QUOTE=Philster] Dig into them and make sure they are not old fence posts or something. Could be concrete or something else, because even though grass won’t grow there, it should have filled in with weeds. [/QUOTE] [QUOTE=Joey P.] Could also be mushrooms. In my lawn, I have one spot, about the size of a coffee can with no grass or anything else. But about every other week all summer it fills in with gross slimey looking mushrooms. The rest of the time nothing grows there. [/QUOTE] Usually, mushrooms grow where they can feed on something decaying underneath. **Joey P** ’s mushroom spot may be over a rotting post or dead tree trunk. Mystery dead spots in a lawn that you recently moved into can be a lot of things. It could be from sloppy application of chemicals. Near the edge, it could be where the owner turned his spreader around and dropped too much Turf Builder®. Maybe he sprayed kill-all around the volleyball posts. One might be where the kids buried old Puff, a little too shallowly. Whatever it is, dig it out, replacing it with garden or potting soil from Targmardepot.