Can old cat food be good fertilizer?

https://www.reddit.com/gallery/1if6bti

created by FroznYak on 01/02/2025 at 13:30 UTC

48 upvotes, 37 top-level comments (showing 25)

Hi, we’ve had to switch cat food for one of our cats due to health issues. Now we have all this bulk cat food that we can’t use. We’re trying to give it away to friends, but everyone is so stingy with their cat food. It seems like everyone else’s cats, just like ours, are on special diets. So my question is, can old cat food be used as fertilizer to improve the quality of soil for growing vegetables and perennials?

Comments

Comment by notthatjimmer at 01/02/2025 at 13:34 UTC

182 upvotes, 3 direct replies

It would most likely draw critters digging in your garden, you don’t really want. Like skunks and raccoons. It might be put to better use if you can feed it in smaller doses to worms and use the castings in the garden. I

Comment by nyxpa at 01/02/2025 at 13:49 UTC

111 upvotes, 4 direct replies

Have you checked local animal shelters? Ours are very grateful to get donations of pet food.

Comment by Frank_Hard-On at 01/02/2025 at 13:42 UTC

26 upvotes, 2 direct replies

We used to dumpster dive dog/cat food to feed to our chickens (we didn't feed them chicken based food though just b/c it seemed weird)

Comment by Podzilla07 at 01/02/2025 at 14:12 UTC

21 upvotes, 1 direct replies

I suggest cutting out several steps of the process and eating it directly.

Comment by MycoMutant at 01/02/2025 at 13:50 UTC

11 upvotes, 0 direct replies

I imagine it would be better to be composted first or else it will probably attract pests/other cats if it is scattered all over the garden.

I might try feeding it to worms but don't know how they'd deal with it if it contains a lot of ground meat. Personally I'd probably try growing mushrooms on it then feed the spent substrate to them or just give it to black soldier fly larvae as is as I imagine they would probably do well with it. Then use the frass as fertiliser.

Comment by michael-65536 at 01/02/2025 at 14:17 UTC

5 upvotes, 1 direct replies

Yes, it contains protein (high in nitrogen), phosphorus, potassium and trace minerals.

However, much of that will be locked away in in big molecules, so it would be better to break it down a bit first.

I would look into composting it. Since it's high nitrogen, you'd need to mix it with something which is low nitrogen but has plenty of carbon, such as wood shavings, chopped hay, dry leaves, coconut coir etc.

Also it will be quite small particles once it's wet. Probably turn into a mush, so the wood shavings or whatever will help get air into it and prevent waterlogging.

If you have an existing compost pile, add a layer to that whenever you're putting other things on, and wet it.

Or mix the whole lot with a carbon rich substance, I'd estimate three or four times as much carbon, drench it, then either put in a compost tumbler or heap it up and turn the pile every day for the first couple of weeks (to get oxygen into it).

Comment by EirPeirFuglereir at 01/02/2025 at 14:41 UTC

6 upvotes, 0 direct replies

I just compost it. Or feed the crows

Comment by omnomvege at 01/02/2025 at 13:44 UTC

4 upvotes, 0 direct replies

Eh, yes and no. It breaks down, just slowly. Idk how beneficial/nutritious it would be for the soil, in terms of NPK… but it’s doable. Your main issue will be critters eating it, so it will need to be buried. If you have a large compost setup, I would say go for it. But definitely don’t add it randomly throughout your soil hoping it will break down.

Comment by Stoned_Druid at 01/02/2025 at 15:13 UTC

4 upvotes, 0 direct replies

Everything eventually returns to the earth and is recycled.

I'd probably bury this though. Only enterprising mining critters would find it then. I've heard you don't wanna mess with their Unions.

Comment by Maxion at 01/02/2025 at 15:20 UTC

4 upvotes, 0 direct replies

You'd need to compost it first.

Comment by SeaShellShanty at 01/02/2025 at 14:59 UTC

3 upvotes, 0 direct replies

I use it indirectly.

I have a kiddie pool with goldfish and water plants. I feed cheap catfood to them, grow the water plants, and use the fish water to water my plants.

Comment by mdixon12 at 01/02/2025 at 15:26 UTC

3 upvotes, 0 direct replies

Cat food is mostly protein, it may be good to bury in the compost pile but I wouldn't spread it around the topsoil.

Comment by HumbleAcreFarm at 01/02/2025 at 17:40 UTC

3 upvotes, 0 direct replies

Feed it to chickens or other domestic fowl. It's good for them and they love it.

Comment by thrust-johnson at 01/02/2025 at 21:12 UTC

3 upvotes, 0 direct replies

I asked a pack of raccoons and they said you should apply it liberally as fert.

Comment by TheMoeSzyslakExp at 01/02/2025 at 22:24 UTC

3 upvotes, 0 direct replies

I had heaps of old Royal Canin dry food, the dental ones - which looks like what you’ve got.

I put it all in the compost and it was fine. I just mixed it in. We didn’t have any issues with rats or possums or anything.

Our compost bin is a plastic bin with a lid though, may make a difference if it’s an open bin/pile?

Comment by Mr_MacGrubber at 01/02/2025 at 15:01 UTC

2 upvotes, 0 direct replies

You sure that’s cat food? Those pieces are huge. Lol

Comment by OverallResolve at 01/02/2025 at 16:36 UTC

2 upvotes, 0 direct replies

It will absolutely stink as it rots. One of the worst smells I have ever had to deal with.

My assumption is that it’s going to be high in carbon with relatively low N. This means it will take a long time to break down (it’s absolutely full of energy, being food) before all the N will be available.

I wouldn’t bother personally having dealt with rotten chicken feed buried in a bed. I almost puked. The smell was worse than poops.

Comment by Ineedmorebtc at 01/02/2025 at 22:06 UTC

2 upvotes, 0 direct replies

Compost it...

Comment by Western_Specialist_2 at 02/02/2025 at 15:07 UTC

2 upvotes, 0 direct replies

Try it. Find out what happens. Then tell us.

I suggest composting it.

Buried a foot or so down in a good pile, I don't think critters are going to smell it. I read about a farmer who composted a few horses this way. With one well buried horse, his farmdog happily slept on top of the compost part without knowing what was going on.