If you already make your own compost and mulch your garden, this post isn’t for you. On the other hand, if you are just beginning with gardening or with organic gardening, here is an introduction to one of the best sources of fertilizer and related to it one of the best ways of controlling weeds.
If you have a small garden, or you are primarily composing kitchen waste, you may prefer to use a composting container. In another post I am going to go into more detail on what this is. In this post I am going to assume you have too much material to compost for a small container.
When deciding where to place your compost, you should keep a few things in mind. Compost has a lot of insects in it when it decomposes. They normally don’t go far from the compost, but this means it is best located away from frequently used areas. Compost has a distinctive odor, it’s not normally thought of as objectionable, but keep it in mind if you are sensitive to such things. Compost rarely attracts animals other than a few harmless insects, but if you have an established problem with things like cockroaches or rodents, they may make their home in the compost because it is warm.
I’m going to risk scaring you off by getting a little bit technical, but hang in there. Even if you don’t understand the underlying principles, composting and mulching are easy and it’s very difficult to go wrong. Composting is simply taking waste material from your garden and decomposing it into a form of dirt, that is very rich in nutrients and can be added to the ground in your garden to make it richer.
Composting is both a chemical and biological process. There are two very important elements in your garden, nitrogen (N) and carbon (C), and composting is a chemical reaction between these two elements. Composting is also a biological process, in that it involves a variety of micro-organisims and insects. Composting will work almost no matter what you do, but will go faster if you provide C and N in the correct proportions and provide good conditions for the biological processes to take place.
N is present in almost anything green (green leaves, grass clippings and so on) and also in animal manure, but it is also present in large quantities in the air we breath. C is present in almost anything else, especially in brown colored things (sticks, dried grass and so on).
When preparing a pile of material to be composted it is important to layer it. Layering is important to improve air circulation and water flow, but also because different materials will contain different amounts of C and N, and it is good to provide a good mix of these in all parts of the compost pile. Ideally you will alternate layers that are high in either N or C, providing slightly more C than N.
It’s much more important to make layers of some sort than it is to get the N and C right, so don’t worry about the N and C unless you are trying to make your compost decompose as quickly as possible. Since there is N in the air, if your compost pile needs to adjust the amount of N it will either release or absorb it from the air as necessary, but this will take a little longer than if the correct proportions are there initially.
Since composting is also a biological process, dependent on micro-organisms, it is a good idea to try to provide a souce of these if possible. They are present in the environment anyway, and will establish themselves eventually, but you can speed things up by adding them directly to the compost pile. A good souce of them is a shovel full or two of compost, if you have already made it in the past. Another good source is animal manure. It’s also possible to buy an inoculant from a garden center, but is perhaps not really worth the money, unless you are in a big hurry.
In general you can put anything in your compost pile that was once alive, so almost any plant or animal material. There are however some things to avoid for special reasons. It is very important to put clean things into your compost, and avoid things that could pollute the ground of your garden: commercial cut flowers will contain too many pesticides, paper may contain poisonous inks and bleaches, and so on. You should also never put diseased plants into your compost, because many diseases can survive the composting process and reinfect your garden. You should avoid things that could attract animals like meats or cooked foods. You should avoid large sticks or wood, unless they are chipped first, because they will take too long to decompose. It is a good idea to avoid putting seeds or potatoes into the compost, because these may not be killed and can turn into weeds. Animal bones will take too long to decompose. Small amounts of paper are not a particular problem, but large amounts of unshredded paper will ‘clog’ the compost and interfere with airflow. Egg shells are good for the compost, because they add calcium which is needed by many plants. It is rarely a problem to put living weeds in the compost, because the composting will quickly kill them.
The use of animal manure in composting or gardening is controversal. In theory, it will provide a good source of N and will compost well. In practice, like everything else you need to insure it is clean. If your manure comes from a commercial farm, it will likely contain traces of all of the food and drugs given to the animals it came from. In addition, if it came from animals that were sick, it will likely contain these diseases. Certified organic farmers who use manure, generally have to use certified organic manure. Manure can contain salmonella and E. coli, which can survive composting to contaminate your vegetables, and make you sick.
There are certainly gardeners who swear by manure in their gardens, but it is my experience that it is of no special benefit and is best avoided or used in small quantities. In any event, fresh manure is high in soluble N like nitrates and nitrites, which can burn the roots of small plants and cause environmental pollution. If you use manure in the garden, it is important that it be well aged and composted so the soluble N becomes fixed and can be used by plants as a fertilizer. Since manure is very high in N it is important to provide a good source of C when composting it, or it may not completly decompose.
Okay, once you have chosen what to put in your compost and layered it, now you have to let it sit. While it it decomposing you should keep it moist, but not water-logged. In addition, it should be able to breath, so don’t store it in an airtight container. Normally compost needs to sit through one complete summer before it is ready to use. Stirring it more often will make it decompose faster, but normally it should be stirred at least once, preferably at the beginning of the summer that it is to sit through.
Typically, a gardener will collect material to compost over the course of a gardening season and build the compost pile at the end of it. The pile would them be stirred the following spring. Stirring usually means to just move the pile from one place to another, but it’s also possible to stir it in place.
What can go wrong with composting? The answer is not very much, at worst it just won’t work until you fix whatever the problem is. If it is too dry, it will just stop decomposing until it is wet again. To avoid the compost pile from getting washed away, surround it with a fence or other border. If it is too wet or doesn’t get enough air, it will become a ‘stinking rotten mess’. Besides smelling bad, this isn’t very serious, just fix the problem and the smell will go away.
Even a ‘stinking rotten mess’ will decompose into compost eventually . It does this with an anaroebic (meaning without oxygen) process which takes longer, but still works. Another example of something that works with an anaerobic process is a septic tank.
If your composting is going well it will get very hot. Perhaps as high as 60C (140F). This is a good thing when it happens because it can kill seeds that may later turn into weeds, and many plant diseases can be killed as well. In addition, heat in turn makes the composting process go faster.
So where does mulch fit in with all of this? There are a few of the same principles behind mulch. Mulching is when you take a material like plastic sheeting, straw or wood chips and use it to cover a piece of ground that you want to protect from weeds. In part this works because it blocks sunlight from anything that might grow under it, but it also works on the same principle as composting. When mulch is rotting in your garden, it is composting, and it will destroy weeds by decomposing them. Weeds, like all growing plants, are high in N. One way that you can increase the effectiveness of mulch is to use something that is as high in C as possible. It should go without saying that it is important to keep mulch at least a few centimeters away from plants that are not weeds, or you may kill them as well.
Some mulches are also effective because they remove N from the ground. Wood chips are a good example of this. Wood chips are so high in C that when they decompose they need a source of N, and they get this from the ground. Since all plants need N to grow this makes wood chips a very effective mulch. Wood chips should be removed rather than be turned into the ground when you are ready to plant, because turning them under will make the ground N poor. Since removing them is a little difficult, they are better suited for areas around rather than in the garden.
Hi Jan,
I don’t think putting boric acid into your compost is a very good idea, mostly because I think this is usually used indoors. In the compost you would have to use a lot, and it would wash away when it rained. I think boric acid has to be kept dry for it to work, doesn’t it? And your compost of course needs to be kept wet.
Compost is rarely the source of the cockroach problem, and maybe it’s possible to figure out where they are really coming from and try to do something there? Maybe it’s possible to move your compost to another location? I guess this is probably easier said than done.
You will never get rid of them this way, but maybe there are things you can do to disturb them and reduce the numbers. For example if you have a way of connecting a hose to a hot water tap, maybe you can flood your compost from time to time with hot water.
Maybe you can figure out when the worst times of the year are for the cockroaches, and try to figure out something to do then. For example, if the problem is worse in the summer, maybe try to empty the compost in the spring. If you can’t empty it, maybe you can spread the pile out over a wider area so it makes less of a home for the roaches, or simply stir it more often.
I’m sorry, except for these things I don’t have any suggestions. I hope this helped a little…
My compost became a breeding ground for roaches. How to get rid of them?
Is mixing of boric acid powder into the pile a good idea, or, it will damge the quality of compost or, be toxic to plants that will grow (when mixed into soil) or to the consumer of vegies grown on such a soil?
i have this same problem with cockroaches, too. my compost was fine last august – june. I emptied it sometime in there and I’m on my next batch and now: roaches! I read that you need to maintain the heat so I probably don’t have the right mix of N and C – if it is 140, then the cockroaches will die (maybe!!!!!)
I want to get a green cone (http://www.peoplepoweredmachines.com/greencone/) to compost my kitchen waste but I’m concerned about roaches. I live in Florida, and no matter how clean you are roaches are pretty much an unavoidable fact of life.
If I install a green cone, am I opening my own roach motel? I don’t have enough lawn waste to keep a regular compost going, so the kitchen scrap option is the best solution for my home.
Any advice out there?
Hi Jacqui,
The compost itself is unlikely to attract roaches per se, but yes it’s possible the roaches will find it’s an attractive home. It probably depends if there are other more attractive places around for them to live.
Like Joan just said, you can not have the problem with one batch but then have it with the next.
If you are willing to take a chance and experiment a bit, you might find different ways of managing the problem. For example, maybe you can pour boiling water on the compost from time to time or experiment with removing and replacing the cover. If roaches are a fact of life anyway, you may find they can be kept to a tolerable level in the compost.
I know of very few people who have concluded they can’t have a composter because of a roach problem, but a little creativity or tolerance might be required.
I hope this helps.
My roach problem continues but I’d have to say that the compost IS the “problem.” It is not really a “problem” as cockroaches naturally eat decaying material (like a dying tree or compost!). So I’m just wondering why it happens sometimes and sometimes not. I would think FL would be highly susceptible. I’m thinking of maybe making my compost an open pile rather than in a bin.
There are numerous parasites and predators of cockroaches, but few of them have proven to be highly effective for biological control. Wasps in the family Evaniidae are perhaps the most effective insect predators, as they
attack the egg cases, and wasps in the family Ampulicidae are predators on adult and nymphal cockroaches (e.g., Ampulex compressa). The house centipede is probably the most effective control agent of cockroaches, though many homeowners find the centipedes themselves objectionable.
Wasps love tomato worms, spiders, etc. so remember wasps are our friends.
Ah, New Orleans, full of cockroaches. I hate them, and I want them all dead. I’d drop a nuclear bomb on them if I thought it would work. It won’t. I might feel differently if they weren’t found in my BED. Palmettos. Yes.
Boric acid is great, but kills all bugs, not just the gross ones. So I’m going to mix up a tasty treat for them (Boric acid, flour, lard, plus something smelly like an onion or coco powder) and gift it to them with my weekly deposit. If that fails, I’m going to start enriching uranium.
I live in Central Texas, where roaches are a problem no matter who clean you are. They love my compost pile. I dont love them. I like the idea of using boiling water to help control the roaches in a compost pile. However, I also have lots of wonderful worms in my compost and worry about cooking them in the process of trying to kill the roaches. Will boric acid also kill the worms?
Hi Cynda,
Thanks for stoping by. While I’m not sure about the worms, I don’t think adding boric acid to your compost pile is a good idea. Boric acid kills roaches because it sticks to their feet and they eat it off. It has to stay dry, and a compost pile is anything but dry. Boric acid is more useful inside for this reason.
So did anyone try the hot water trick? Any success?
I’m having the same problem and I’ve found that after I turn the pile every week and cover the pile with black plastic. If I keep the water on the pile only and spread a heavy film of diatomaceous earth around the pile it will keep the quantity down.
I built a tumbler. I added plenty of greens, yard clippings, fruit peels, etc etc. I was not aware of the N & C balance required, and now the composter is 2/3 full but mostly with N high materials. I have started adding C rich materials, but nowhere close to matching the amount of green material. Should I just continue to add browns?
I noticed there are a lot of fruit flies, I mean A LOT. There is a lot of drainage from the tumbler, the flies seem to be happy about all that.
Any suggestions?
Hi Andrew,
Manure is really high in N, and it’s certainly possible to get too much of this. Grass clippings and other green things are also high in N, but not as high as manure, and it’s harder to get too much.
Compost is pretty forgiving, and if you get the balance of N and C a little wrong, it doesn’t really matter. There is N in the air, and compost can give off a little extra or absorb a little if necessary, but this is a slow process. It’s mostly depends on how fast you want the compost to decompose.
Yes, compost has a lot of flies. Mostly they are pretty harmless, for example mosquitoes don’t usually like compost. I would say if the flies bother you, it’s best to locate the compost some place out of the way.
Hello!
I just began a compost pile, and I am a beginner gardener and composer. My house already has a roach problem and it seems like the compost would attract them…should I just skip out on composting altogether?
And if so, what can I use to fertilize my watermelon sprouts besides manure? (eww!)
Hi Jessika,
I personally wouldn’t let the fear of roaches keep me from starting a compost pile, but you do need to keep an eye out for potential problems. I suggest starting small, maybe using a container like this one:
http://www.patnsteph.net/weblog/2006/04/container-composting/
Then if you do end up with a roach problem that you can’t solve any other way, you can just bag up your compost and throw it away.
Another possibility might be to do what’s called trench composting. This is where you dig a hole in the ground, put your waste to be composted in it, then cover it with dirt again. The ground will sink, so be sure to make a bit of a heap. After you do this, you can grow your plants on top of it. It might be best to wait a little bit, but in theory you can plant on it right away.
As for fertilizing your watermelons, you can try growing green manure plants nearby, like peas or beans. This isn’t really a complete substitute for compost, so if you can’t make it yourself you might need to buy some…
I started composting last year. The city of Phoenix makes composters out of the top half of old, plastic garbage cans. The drill holes in the sides to make them breathable, and they only cost $5.
At first I put food scraps, paper, leaves, etc. in it. After a while, german roaches moved in. We have never had a roach problem, and they did not seem to ever make it into the house.
I got nervous about them doing so after seeing a few near the house, and my neighbor’s house. We live on an acre and a half, so the composter is several hundred feet away, near my garden.
i let it dry out, spread it out and applied a lot of boric acid (I made a ring around the area i spread it out in first.
After letting it sit for a few days, i put it all back in the composter.
We have since added a flock of chickens to the family and I now only use their manure, straw, and small amounts of paper.
It doesn’t appear the roaches have returned, and I’ve been doing this way for about 7 months now.
Hope this helps,
Kate
Thanks Kate!
I live in Spain, and I to have a cockroach problem,18months ago I brought a square plastic compose maker, and this year I havelots of roach grubs.
I have read all your possible sollutions,but do not feel confident with any, I am trying an insectacide called 1 ANO if sprayed over an area any roach that crosses it will die,I have sprayed around the edges of my compose and hope that will stop them.
the name ! ANO in Spanish means 1 year, and that is how long it lasts, (fingers crossed)
I have a new house on a new plot in Western Australia. There are no plants in the ground yet and the “soil” is terrible. I have lots of kitchen waste so decided that a compost bin would be a good way to improve my soil and reduce the amount of landfill waste. Before I bought the bin I was digging holes in the ground and burying all the peelings. After I got the compost bin it took less than 4 weeks for me to discover cockroaches scuttling away when I lifted the lid. Having read several forums on the issue I accept that if I want to be green I just need to become less squeamish. However what does concern me is this. Is my kitchen waste merely feeding the roaches or are the roaches actually helping the composting process. I’m originally from Scotland where I have never seen a cockroach – except in the zoo!
Hi Barbara,
Thanks for your comment.
Every time I try to say something about the climate or environment in Australia I get in trouble. I’ve never been there, and the impression I get is everything is totally different from here in Amsterdam. A good person to ask might be Kate at Vegetable Vegabond who’s an experienced gardener who actually lives in Australia.
I think in general, while cockroaches might be a useful part of the process and you might have to tolerate them a bit, you also need to do everything you can to discourage them. Certainly if I found an overwhelming cockroach problem in my compost, I would stop making it.
I doubt it’s a case of you feeding them with your kitchen waste, but rather you might be attracting them with a nice place to live. If making compost in the ground means you have less of a problem than with a bin, I would consider going back to this. You might also experiment a bit with putting it in the sun or shade, or maybe a wet or dry place. You might try an open vs closed bin.
If you suspect some item in particular might be causing the problem, you might want to discard this instead of composting it. In particular, you want to avoid putting cooked or processed foods into your compost, especially meats. You should really only compost vegetable, fruit and garden waste.
If you have a large enough yard, you probably want to move the compost as far away from your house and neighbors as you can.
If you look into it, you might find the true source of the cockroaches is really something else, and they are just using your compost as a place to live. For example, maybe a nearby building is infested? Maybe something can be done about that?
In the end it probably comes down to what you, and maybe your neighbors can tolerate.
I hope this helps!
We have a big fixed compost heap – about 4 or 5 cubic meter that we built ourselves using brick and mortar with a whole at the botom for retreavsl of compost that is ready. For years we never had any problems with cockroaches but over the past couple of months we have developed quite a problem with far too many if them coming into the house.. Especially at night after the light. I dont want this at all!! At the same time we want to be part if natural living and of the whole recycling approach. After reading this article and others and the many of the replies, today we decided to open up the whole of our heap and this is what we found: countless bigger and smaller ones nesting in areas inside the heap that are DRY. We are scooping out all the great compost at the botom of the heap and returning the rest with some wood ash inbetween and end with a good watering. The compost heap sits in a very hot spot so hopefully soon we will have a good ‘cooking’ process going that will not be attractive for the cockroaches. What may have gone wrong we think us that we did bot have a balanced amount if dry and green material and our heap gets too full without enough airating and water. We look forward to a great outcome and will share results.
Hi Anna-Mari,
Thanks for leaving the comment. Looking forward to hearing more!
Patrick