When you first start gardening you will hear people talk about compost, composting, and using compost in their gardens, but what is compost really? Is all compost the same? Is compost the magic bullet in greater gardening? Let’s break it down.
The Bog Standard Definition of Compost
Compost is, broadly speaking, broken down organic materials. This definition is wide because it can include any sort of organic materials. Plants, animals, food scraps, manure; these are all organic materials that can be broken down and turned into the brown dirt pile we refer to as compost. That’s a fine definition and all, but how do you know compost if you see it?
The Look, The Feel, of Compost
Compost, while made of many things, looks a lot like topsoil. It’s a dark brown crumbly dirt like mess of organic material that is moist, but not wet nor dry. Good compost has a very neutral non-offensive odor while bad compost may smell like ammonia, rot, or other vile scents. Compost that is finished will not be hot or even warm really, but compost that is still processing will have a higher temperature internally due to all the microorganisms working inside. Finished compost shouldn’t contain any recognizable scraps and should have a fairly even crumbly texture.
So we know what compost looks like, and we know it’s made of organic compounds, but is it all the same? While in general terms it doesn’t matter what type of organic material decays down to be called compost, functionally no two composts are the same. On top of this, compost with improper materials in it can be more harmful than beneficial for a garden.
A Compost by Any Other Name: Different Types of Compost
Not all compost is created equally. Many people assume you get compost by dumping just any organic scraps you have into a pit or barrel and magically compost comes out months later. While it is true that some dirt like substance will be formed in most cases, not all of this compost is going to be good for your garden and not all compost has the same nutritional values. There is a proper way to compost organic scraps, but in general the biggest mistakes are making a compost pile too wet, to stuffy, or out of too much of one thing.
Some people compost animal scraps while other people may compost general food waste. Each of these are fine in moderation, but too much of either of these will leave you with a gross wet goop instead of a nice compost bed. Compost needs a mix of dry and wet components from all sorts of organic materials, and it needs to be aerated and well mixed.
Even after following all these steps, no two compost piles will have the exact same nutrition, so it’s important that you’re aware of what goes into your compost and how that will effect its usefulness as a component of your garden. A home gardener will really have no way to tell one compost pile from another, so it is always a good idea to attempt to make a well balanced compost pile that can act as a general purpose fertilizer. This all comes down to balancing what you put in and treating your compost pile properly. While great compost can be instrumental in growing things like fresh tomatoes, bad compost can ruin a crop!
Does Any Organic Material Compost?
While all organic materials will break down eventually, not all organic material composts well. In addition this some organic materials that might have composted well get treated when they are used initially and become unusable for composting.
In general you should never compost things that contain pesticides or herbicides as it will make the compost harmful to the plants you intend to use it for. Dairy products don’t compost well and should be avoided as they can attract pests and bad bacteria. Both coal ash and black walnut wood can release compounds that are harmful to plants. Pet wastes and disease ridden plants should be avoided as they can contain pathogens that can harm the plant or find their ways into food grown with the resulting compost. Lastly, fats and oils can cause problems with aeration and pests and should be avoided if possible.
That’s a lot of stuff to avoid but knowing it can be a problem is more than half the battle!
Beware “Free” Compost!
As we’ve just discussed, compost looks like compost even if it’s got bad stuff in it! If you’re being offered free compost you might be in for more than you bargained for. While it is unlike the individual offering you compost is being malicious it is likely that they were not aware of all the stuff you should avoid putting in the compost pile!
If you do decide to consider taking free compost, make sure and inspect it first. If you see it’s unfinished and has chunks in it, decline the offer. Similarly if it has a terrible odor it should be avoided. Finally, and we really hate that we have to warn you about this, you need to check compost for trash. Some people use their compost piles as a garbage heap and this produces bad compost in addition to being a gross thing to do in the first place.
Compost Is Complex
We hope this has highlighted the fact that compost isn’t just organic matter turned to dirt and that there’s more to compost than meets the eye. If this has peaked your curiosity the next step for you is to start making your own compost and learn the process for yourself. There is no substitute for experience when it comes to gardening, so get out there and make something!