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Question AFrequently asked questions about composting

There are lots of questions about the different aspects of home composting that we get asked. Here we hope to provide you with all the answers!

For the most commonly asked questions we have a Composting Troubleshooting Guide and below we answer the top 10 queries that you have asked us over the last few years.

However, if you have more specific queries we have answered many of the common questions that are asked and gathered these together under the main headings outlined below. For more information on specific systems go to our downloads section.

If you have any other queries on any aspect of home composting please contact us.

Your Top 10 Questions Answered

1. Is there anything I can do to speed the decomposition process?

2. There are hundreds of flies in my compost system?

3. My compost smells, what can I do?

4. My eggshells aren’t breaking down in the compost system, why?

5. Turning my compost is difficult is there anything I can do to make it easier?

6. What can I do to reduce the weed seeds in my finished compost?

7. Is there something wrong all my slugs and earthworms are around the lid of the compost unit?

8. Will ashes from the fire compost?

9. Are rodents a problem when composting?

10. How will I know when my compost is ready to harvest?

 

1. Is there anything I can do to speed the decomposition process?

Shredding or chopping the materials going into the compost system, regularly turning your compost to add oxygen, and adding nitrogen rich products such as nettles, coffee grounds, small quantities of grass cuttings or human urine all can help to speed up the decomposition process. ↑ Top

 

2. There are hundreds of flies in my compost system?

During the summer wormeries and compost bins can be affected by fruit flies. They are harmless and are attracted to the vegetative food scraps that you are adding to the system. To minimise the number of fruit flies simply leave the lid off the compost bin on a sunny day for 2-3 hours. Then cover the contents of the compost system with wet sheets of newspaper and replace the lid. The idea behind this is that you are limiting the contact the flies can have with the vegetative food scraps. Better yet, bury the food waste within your composter and/or cover each new addition of food waste with a layer of shredded paper, sawdust or autumn leaves – this will also add “browns” to your food waste “greens”.↑ Top

 

3. My compost smells, what can I do?

Your compost should never have an offensive smell. This may happen if your compost is too wet  meaning that there is not enough air available to the composting process (remember the 50:50 mix of green and brown material). If your compost is offensively smelly look inside the unit. If the contents look slimy and wet add “brown materials” such as sawdust, straw, shredded paper or cardboard to the unit to soak up the moisture. These should be mixed in as thoroughly as possible. If it’s not too much work, you can lift the whole bin off the pile and turn everything back into it, adding the dry materials a little at a time as you go.

On the other hand if your bin is too dry, then the composting process will be very slow. This can happen if the weather has been warm for a while. To moisten the contents, simply water the material with a watering can slowly and thoroughly, turning as you go to ensure consistent wetting throughout. ↑ Top

 

4. My eggshells aren’t breaking down in the compost system, why?

Eggshells are made up of a protein membrane and a calcium carbonate (lime) coating. The lime is valuable in your compost or soil, but cannot be digested by the bacteria, fungi, and invertebrates that do your composting for you, so the shells remain whole and visible for a long time. Crushing your eggshells will make them less noticeable in the compost you harvest. Alternatively putting your eggshells in the oven for 10 minutes will make them brittle and easy to powder (but please don’t waste energy by turning on the oven specially for this – just pop them in the bottom when baking something anyway.↑ Top

 

5. Turning my compost is difficult is there anything I can do to make it easier?

Regularly turning your compost is important to keep it aerated and to thoroughly mix the wet and dry / green and brown ingredients together. Home-made compost systems are generally easy enough to turn – however it is difficult to turn the contents of typical plastic compost bins due to the narrow opening at the top of the bin. If you are about to start composting or have just harvested some compost place a drainpipe drilled with holes into the centre of the empty system. When you are adding material add the material around the outside of the drainpipe (never put material to be composted into the drainpipe as this will block the hole). The holes in the drainpipe will allow a continuous supply of oxygen to the bottom of the compost bin. Alternatively stabbing the material with a fork will introduce some oxygen or you can purchase a spiral compost mixer that can be described as a giant corkscrew. ↑ Top

 

6. What can I do to reduce the weed seeds in my finished compost?

There will always be a small number of weed seeds within the finished compost. When you are using a turning system you will have fewer as high temperatures generated will kill the weed seeds, however when cool composting (using a compost bin) the heat generated is not hot enough to kill the weed seeds. You can leave the weeds out to dry in the sun and this will kill the seeds, you can cut the flowering head off the weeds as this is where the seeds are or you can drown you weed seeds. To drown the weeds simply submerge your weeds in water and cover to eliminate light and leave for 2-3 weeks. At the end of this time you should have your dead weeds that can go into your compost system and a strong-smelling liquid. This liquid is full of nutrients so use it to feed your growing flowers and vegetables. ↑ Top

 

7. Is there something wrong all my slugs and earthworms are around the lid of the compost unit?

If your composting system is working reasonably well, worms and other decomposers will find their own way in, even if the bin is placed on concrete or tarmac. Adding worms from your garden may not be helpful, as some species of worms need to live underground in soil and will need to escape from your bin or may die in there. Worms make their way to the lid of the compost bin. Don’t worry – this is a good sign and they will make their own way back into the material to be composted. ↑ Top

 

8. Will ashes from the fire compost?

If you think about it, the energy has already been extracted from ashes so they have no food value for the decomposing organisms, therefore they do not help the composting process. Also, they can block up the valuable air spaces in your compost pile. On the other hand, ashes are a valuable fertiliser, being alkaline and containing potassium (pot-ash). So you can spread ashes thinly on your garden or mix them with your finished compost.

However, coal ash contains a lot of toxic chemicals. But, if you are burning turf, briquettes, charcoal or wood, then the ash from these can be composted. ↑ Top

 

9. Are rodents a problem when composting?

Simple answer – yes they can be, but not if you manage your composting properly.

Rodentsare attracted to cooked food, therefore it is recommended to avoid adding cooked food into your compost system unless your system is vermin-proof such as a metal-enclosed tumbler or digester. They are also attracted to the compost system as it is a warm environment. You need to ensure they cannot enter the system, purchase a compost bin with a base on it or alternatively create a base out of strong meshing wire placed under the bin and wrapped up around the sides. Planting lavender, garlic, cat mint, rosemary, and  other strong-smelling herbs around the compost system also helps to deter rodents, as they don’t like the smell of them. You can sprinkle pepper on the ground around the compost bin as an irritant, and also it has been found that if you are more active in turning your compost you are much less likely to have problems with rodents – they like undisturbed conditions.↑ Top

 

10. How will I know when my compost is ready to harvest?

You will know when your compost is ready to harvest as it will look like a dark brown, crumbly soil and you should not be able to recognise any vegetative food scraps or garden materials. It should also smell good, like rich soil or the smell of the forest on a wet day. If your compost smells bad, do not use it as it will be harmful to plants. Turn it and leave it for longer, as it has not gone through the whole process yet. ↑ Top

Composting & Materials

1. What can I compost at home?

2. What about ashes from the fire?

3. And what about egg shells?

4. What about herbicides and pesticides?

5. Can vacuum dust/bags or lint from dryers be composted?

6. Can pet wastes be added to home composting systems?

7. Can weeds be composted?

8. Can diseased or insect infected plants be composted?

9. Can sawdust and wood shavings be used in compost?

10. Can newspaper and cardboard be composted?

11. Do I need additives?

 

1. What can I compost at home?

In general, any plant derived material can be composted at home. Due to potential odours and pests, it is not recommended to compost animal-derived materials such as meat, fish, bones, egg shells, skins, fats, cheese, etc. in your home composting system (see Note below). Below are two charts that list the materials that are acceptable for composting. The Good, the Bad and the Ugly chart lists the materials that can and cannot be composted and the reasons why.

Note: There are home composting units, such as the Big Pig and the metal food digester, that are suitable for animal-derived materials, if used properly. ↑ Top

 

2. What about ashes?

If you think about it, the energy has already been extracted from ashes so they have no food value for the decomposing organisms, so they do not help the composting process. Also, they can block up the valuable air spaces in your compost pile. On the other hand, ashes are a valuable fertilizer, being alkaline and containing potassium (pot-ash). So you can spread ashes thinly on your garden or mix them with your finished compost.

However, coal ash contains a lot of toxic chemicals. But, if you are burning turf,charcoal, briquettes or wood, then the ash from these can be composted.

Ashes contain Potassium, an important plant nutrient, but tend to be high in pH (alkaline). As the composting organisms like a fairly neutral pH environment, not too acidic or not too alkaline, adding too many ashes will inhibit the composting process. However, ashes from burning peat briquettes or wood in a fireplace or stove as well as ashes from burning charcoal in a BBQ can be incorporated directly into the soil in place of using lime, especially in acidic soils so typically found in Ireland. Be sure to spread the ashes evenly over the planting area and dig in with finished compost and organic fertilisers when you are preparing a planting area for new plants. Ashes from burning coal should not be used due to the fact that they contain substances that may be toxic to life within the soil and to the plants grown in it.↑ Top

 

 3. How about egg shells?

Eggshells are made up of a protein membrane and a calcium carbonate (lime) coating. The lime is valuable in your compost or soil, but cannot be digested by the bacteria, fungi, and invertebrates that do your composting for you, so the shells remain whole and visible for a long time. Crushing your eggshells will make them less noticeable in the compost you harvest. Alternatively putting your eggshells in the oven for 10 minutes will make them brittle and easy to powder (but please don’t waste energy by turning on the oven specially for this – just pop them in the bottom when baking something anyway. Then the powdered shells can be added to your compost heap or directly onto your soil. ↑ Top

 

4. What about herbicides and pesticides?

Many people use herbicides and pesticides on their lawns, planting areas and garden to control pests and weeds. Both herbicides and pesticides contain toxic chemicals (most are made from petroleum); these toxic chemicals are formulated to kill plants or pests. Aside from the fact that these chemicals can pollute the environment, many of them are linked to causing cancer. So the first thing to consider is: Do I really need to use them and what sort of alternatives are there to prevent or manage pest and weed problems?

Pesticides: Many pest problems result from plants grown in weak or unhealthy soil; if the soil is deficient, then the plants grown in them are weak and more susceptible to disease. So the first line of defence against pests is to improve the health of the soil. Guess what? Adding compost to soils helps restore the balance of life in the soil and feeds the ecosystem of life in the soil so it can suppress any disease, such as mould or fungus,  that might otherwise dominate in an unhealthy soil. Secondly, check to see if you are growing the right plant or variety of plant in a location that is suitable to meet its needs. For example, a plant that likes a lot of heat or light will not thrive well in a dark and damp location. Again, a weakened plant will attract disease. Third and most important is that pests can be a problem no matter what you do so, if you prefer not to use toxic chemicals in your garden, then think about non-toxic alternatives. For example a diluted soapy solution can be sprayed onto plants to control aphids. Likewise, slugs and snails can be controlled by sprinkling crushed egg shells, coffee grounds, or hair from your local hairdressers in a circle around plants you want to protect or placing submerged plastic cups with beer into the soil to attract and drown them. There are many alternative to the use of toxic chemicals and if you would like to learn more about this subject, search the internet. One very useful site is www.watoxics.org/healthy-homes-gardens-1 which has links to other sites as well.

Herbicides: These kill unwanted weeds. Weeds can be prevented by using mulch in planting areas. Then any weeds that do pop up can be easily pulled out (especially before they go to seed). In lawns, weeds can be pulled by hand before they go to seed to prevent them from spreading even more. Leguminous plants such as clover in lawns are actually beneficial as they fix nitrogen from the air and store it in the nodules of their roots to become available in the soil for other plants. Cutting your lawn more often also prevents many weeds from going to seed and thus helps keep them under control. In some cases, for well-established lawns, perennial weeds such as buttercup can be a problem and herbicides may be the only solution to eliminate them without tearing up the entire lawn and starting over. But before using herbicides, ask yourself, is it really a problem?

If you’re not totally convinced that alternatives work and insist on using these toxic chemicals despite their high cost and potential effect on the health of your family and pets, most of these chemicals are designed to break down over time, often several months. Composting actually accelerates their break down and studies have shown that compost made at centralised facilities where high heat is attained during the composting process actually reduces pesticide and herbicides to levels lower than those found on fresh produce at the store. Scary isn’t it? However, that said, some of these chemicals break down into substances that are more toxic that the original chemical itself. Therefore, you have several choices: 1) stop using them as noted above; 2) don’t put diseased plants or ones treated with pesticides in your compost pile; or 3) put herbicide treated lawn clippings in your pile but be sure to give it enough time to fully break down (6 months to a year) and/or manage them in a “hot” turning system. Remember that herbicides tend to be less toxic than pesticides. ↑ Top

 

5. Can vacuum dust/bags or lint from dryers be composted?

The answer to this question depends on the type of carpet you have at home and the clothes you are drying.

Vacuum Bags: If your home contains carpet made from synthetic fibres (most wall-to-wall carpets), then the vacuum bag should be disposed of in your rubbish bin. If you have no carpets at home or if they are made from wool, cotton or linen, then, yes, the contents of the vacuum bag can be composted. Many vacuum bags are made from synthetic materials. These will not break down in the compost pile. If you want to compost their contents, simply cut the bag open and spread the contents onto the compost pile and mix them in. If the bag is made of paper, the bag can be composted as well. However, the bag and its contents should not be added to the compost pile as is. For paper vacuum bags, simply cut the bag open and spread the contents on top. Then cut up the bag and mix it all thoroughly into the pile.

Drier Lint: If you are drying clothes that are made of synthetic fibres, then these will not break down in your composting system. If the clothes you are drying are made of cotton, wool, linen or other natural plant or animal derived fibres, then they can be added to the compost pile. Try to pull the lint apart before adding it to the pile. ↑ Top

 

6. Can pet wastes be added to home composting systems?

Pet wastes from vegetarian animals, such as rabbits, gerbils, hamsters, guinea pigs or birds, can be composted at home. Plus those of you with horses can compost their manure. Just remember that all pet poop or manures are high in nitrogen so they need to be balanced with “brown” materials that are high in carbon, such as straw, dried leaves, shredded paper, etc. Pet wastes from carnivores, such as cats or dogs should not be composted in holding, turning or vermicomposting systems. This is because this kind of pet poop may contain diseases that can spread to humans. For example, cat poop can contain a pathogen that affects pregnant women. These pet wastes can also attract pests (flies) and create foul odours when composted in piles or a worm bin. That said, there are three ways to manage carnivore pet wastes at home: 1) flush them down the toilet; 2) bury them in non-food producing areas of your garden (see brochure on food burial); or 3) use a dedicated green cone or buried digester for just animal waste. If you choose to do the later, then handle the material with care, wear rubber gloves and/or wash your hands afterwards, and only use the resultant digested material in non-food producing areas of the landscape around your home. ↑ Top

 

7.Can weeds be composted?

Yes and no. Most weeds can be safely composted without the worry of the finished compost spreading weeds back into your garden. In general, there are two types of weeds: annuals that spread by seed and perennials that spread by root or rhizomes.

Annuals: For annual weeds like chickweed, try to pull them out of your garden before they flower and go to seed. For dandelions, be sure to chop them up with a shovel or cut them up with pruning shears before adding them to the pile. For annual weeds that have gone to seed, simply remove the flower or seed head before adding them to the pile. If this cannot be done easily, then they should not be added to cool “holding” composting systems as many weed seeds will persist and survive the composting process. If you want to compost weeds with seeds, then you have a better chance at killing the weed seeds if they are composted in a hot “turning” system. The high heat, in excess of 60°C, will break open the seeds and expose them to decay. When turning the pile, be sure to turn the sides to the middle and middle to the sides so that all composting materials can be exposed to the core high temperatures of the pile.

Perennials: Some perennial plants, such as docks, briers, ivy and bindweed, are difficult to compost. It may be best to rot them in a bucket or barrel of water, and you can use the resulting liquid as a plant feed. The plant will turn mushy and rotten and can then be added to your compost pile.

Japanese knotweed is fast becoming a problem in Ireland, and is so invasive that it is illegal to compost this exotic plant, as it can reproduce vegetatively from even a tiny piece. You should contact your Local Authority for more guidance. ↑ Top

 

8. Can diseased or insect infected plants be composted?

Some diseases will persist when composted in a cool “holding” system, so if you are using this type of composting system for your garden materials, then leave them out. On the other hand, hot “turning” systems can be used to kill diseases or insects found on infected plants. You will be most successful if you can build a big enough pile to reach temperatures in excess of 60°C and if you can turn the pile at least twice making sure that the sides are turned into the middle so that all materials are eventually exposed to the pile’s hot core. Please see our brochure on “turning” systems. ↑ Top

 

9. Can sawdust and wood shavings be used in compost?

This depends on the type of wood and whether or not the wood is painted or preserved. Most wood shavings from clean timber can be composted as long as they are mixed with wet and green materials (please see the composting essentials section of our general home composting brochure). Sawdust or shavings from cedar contains an oil that is resistant to decay so it will not compost as easily as saw dust or shavings from other trees. Sawdust from painted or preserved wood contains toxic chemicals so these should not be used for composting. ↑ Top

 

10. Can newspaper and cardboard be composted?

Yes.  Any paper or cardboard that is not coated with plastic (milk cartons or juice boxes, for example, are coated) can be composted All other paper can be composted including coffee filter and tea bags (though some tea bags contain some polypropylene that will remain as little scraps of netted plastic after the composting process – but cause no problem. Remember that paper is a “brown” material and on its own will take a lot of time to break down. Therefore, it needs to be balanced with wetter “green” materials for composting. Whole sections of newspaper or many pages of paper tend to mat in the composting pile. By shredding and separating the paper or cardboard, it will break down more quickly. Lastly, if the paper is dry, it will not break down. Therefore, make sure that the pile has sufficient moisture to promote adequate decay. ↑ Top

 

11. Do I need additives?

No. All of the composting organisms you need are already present in the materials you have for composting. Given the right conditions- proper blend of “green” and “brown” materials, adequate moisture and sufficient air- you create the right environment for the ones you want to multiply and they take off. As materials break down, they create heat. As the pile gets hotter, a succession of different microbes evolves to thrive in higher temperatures. As the pile cools, then the spores of the cooler microbes emerge from dormancy and become active again.

There are many compost starters and activators available for sale on the internet and from retailers, such as DIY stores, garden centres or hardware stores. Some of these contain a mix of microbes, enzymes or nutrients while others are simply small boxes of bags of nitrogen fertiliser which are sold to accelerate composting of leaves. So the question is: why spend money on starters or activators when you really don’t need them. If you follow the basic rules of thumb for composting (please see the composting essentials section of our general home composting brochure), then you will be successful with making good compost without these costly additives.

By regularly turning your compost to add oxygen, shredding the materials going into the compost system and adding nitrogen rich products such as nettles, coffee grounds, small quantities of grass cuttings or human urine all can help to speed up the decomposition process. ↑ Top

Composting Bins and Systems

1. Do I need a bin?

2. What system is best for me?

3. What systems compost just food scraps?

4. I have so many leaves, what can I do with them all?

5. I only have grass cuttings to compost, what system would suit me best?

6. How much space is needed for composting?

7. Where should I place my composting bin?

8. Should I layer materials into my compost bin?

9. Should I add soil to my compost bin?

 

1. Do I need a bin?

Not really. Composting can be easily done in free standing piles without any structure at all. In Ireland’s wet climate, covering the pile with a plastic tarpaulin, old carpet or plywood keeps the pile from getting too wet from the rainand from getting too dry from the wind and sun. The advantage of a composting bin is that it helps keep materials organised, neat and tidy. For families with a small garden and not many food scraps, a small plastic bin is a simple way of holding materials together and preventing them from getting too wet or too dry. Simple holding units can also be constructed by pallets, or bought or built using various DIY designs. For larger properties, a multi-bin turning system keeps piles separate so you can work them through the composting process more efficiently if you want to make compost quickly. It is also more space efficient because piles can be square or rectangular within a structure instead of triangular or cone shaped as a pile. ↑ Top

 

2. Which system is best for me?

The first question is – what materials do you have to compost? Is it mainly food/kitchen scraps and peelings, or garden waste, or a combination of the two? There are a lot of ways to make good compost- the best method is the one that is most convenient for you. There are many different systems on offer, including ones supplied by your local authority. Some can be expensive so the question becomes… “Can I make my own? Luckily you can, but you need to figure out which is the right system for you. Check out our Traffic Light System for the best system for you. ↑ Top

 

3. What systems are best for composting food scraps?

Food burial, wormeries, Green Cones, Bokashi and electric under-sink composters. Please see the various downloads on each of these systems for more information. ↑ Top

 

4. I have so many leaves, what can I do with them all?

Autumn leaves are a precious material as they can be mixed with “green”  materials such as grass cuttings or food scraps to get the proper balance of materials for optimal composting. In the autumn, when leaves become available, simply pile them up, place them into a holding bin or leaf mould holding bay (a simple ring of wire mesh will do) or store them in plastic bags until you need them. If they are placed into a holding bin and are kept moist, they will eventually break down on their own over time. In 1-2 years, a crumbly leaf mould will be produced that is ideal for use as a general all-purpose mulch or as a soil amendment for acid loving plants such as raspberries, blackberries, blueberries, pine trees, rhododendrons or azaleas. ↑ Top

 

5. I only have grass cuttings to compost, what would suit me best?

Composting grass cuttings on their own is difficult and can produce a slimy smelly mess. So instead of collecting grass cuttings, consider GrassCycling where you leave the cuttings on the lawn. Our GrassCycling brochuregives you all the information you need to be successful and help you get started. As GrassCycling may not be appropriate at all times of the year, cuttings can be collected and composted as long as they are mixed with other “brown” materials such as bush trimmings, leaves, straw or wood shavings. Please see the composting essentials section of our general home composting brochure. ↑ Top

 

6. How much space is needed for compossting?

This really depends on how much material you have for composting and the type of system you choose. If your outdoor space is limited and you have a lot of material, a turning system will make compost more quickly and save space. If you are not concerned about how fast you make compost, then multiple holding units can be placed all together or spread around your garden to handle materials as they are generated. In all cases, be sure to allocate enough space around the front of your bin so you can work the system: mix and blend materials before adding them to the composting system as well as harvest the compost from your system. If you are using a holding bin and want to turn the compost to speed up the process, be sure you have enough space to place the bin next to the old pile so you can turn materials into it. ↑ Top

 

7. Where should I place my compost bin?

Ideally, the spot you choose for your pile or bin should be in a flat, shady or partially sunny spot on bare soil. This keeps materials from drying out in the hot sun, allows beneficial organisms, insects and worms to gain access to the rotting material from the soil, and promotes better aeration and drainage. But if you only have a concrete or tarmac surface, don’t be put off. You can still compost, but it may be a bit slower than if it were done on grass or soil. Make sure you choose a place where you have enough room to easily add ingredients to the bin and get compost out. It’s best to keep the bin or pile away from the house or the neighbour’s home just in case there are problems with odours or pests, especially insects. And if you place it in a far-off corner, make sure you don’t neglect it – treat it like a microbial farm, that will thrive with your help and may fail if you ignore it. ↑ Top

 

8. Should I layer materials into my compost bin?

This is one of the myths of composting that needs to be dispelled. As the composting microbes need a balanced diet of “green” and “brown” materials, layering creates zones that are too rich in “green” materials and too rich in “brown” materials. The “green” materials will break down quickly and may become slimy or compacted if they are left in layers. Likewise, “brown” materials break down really slowly so they will just sit there and not do much but take up space in your bin. Layering can be a good way to proportion “green” and “brown” materials but it is essential to mix materials with a pitch fork so that materials are blended evenly together. And don’t forget to add some moisture if materials are too dry. ↑ Top

 

9. Should I add soil to my compost bin?

Here is another old myth of composting. Adding a layer of soil can suffocate the compost pile and fill in precious air spaces needed to allow the pile to “breath.” So please do not add shovelfuls of soil to your compost bin. This also takes up valuable space within your bin. Conversely, you don’t need to be fanatical about removing all soil from the roots of plants or bits of sod. Some soil is good as it contains a wide variety of microbes and can help jump start the composting process – so can adding a little bit of finished compost to a new batch. ↑ Top

The Composting Process

1. Why does my compost pile smell bad?

2. What do I do if I find rats living in or around my compost bin?

3. What do I do if there are lots of flies in my composter when I open it?

4. What do I do if I find slugs and/or snails in my compost pile?

5. Do I need to water my compost pile?

6. Should my compost pile or system be covered?

7. Does compost need to be turned?

8. How do I speed up the composting process?

9. Should I add worms to my compost bin?

10. How long does it take to make compost?

11. How do I know when the compost is ready?

 

1. Why does my compost pile smell bad?

There are many reasons why your composting bin or pile can smell bad, including:

  • The pile is too wet due to being exposed to rain or because the pile is made with predominately wetter food scraps – when the pile is too wet it excludes vital oxygen and the compost turns smelly.
  • The pile contains too many “green” materials such as grass clippings and food scraps.
  • The pile contains food scraps containing animal products such as meat, fish, skins or dairy products.

If you find that your pile smells bad, try to analyse what the causes are. If it is too wet, turn the pile and add some drier “brown” materials – get as much air space and air pockets into it as you can using straw, crumpled-up cardboard, and other bulky materials. If the pile has become too wet due to excessive rainfall, you can also cover the pile with plastic, old carpet or some plywood to keep the rain out. If the pile contains too many “green” materials, turn it and add some coarse “brown” materials to balance nutrients and add some air space within it. If you are putting meat or other materials of animal origin into the food scraps to be composted, then collect only vegetative kitchen scraps for composting (animal-derived materials can go in a Pig or metal digester bin.↑ Top

 

2. What do I do if I find rats living in or around my compost bin?

There are two reasons why rats are attracted to a compost pile. One is that food scraps are easily accessible or that you are adding high protein food scraps such as meat or fish leftovers, bones, skins or guts that they like to eat. Also remember that vegetative food scraps need to be buried within composting garden and landscape materials, not placed on top. You might consider keeping a stock of sawdust, shredded paper, or autumn leaves next to your compost bin to cover new additons of food waste. You should avoid adding any food scraps of animal origin to the pile at all (animal-derived materials can go in a Pig or metal digester. The other reason is that compost piles can be a warm and dry home for nesting. This is especially true in winter months. If you are burying vegetative food scraps in the pile and you find that rats are nesting in your bin, you can turn the pile to disrupt nesting behaviour. To discourage rats from getting in your compost bin or pile, plant lavender or other strong-smelling herbs around the bin as they do not like the smell of it – it can also be helpful to sprinkle pepper around the bin occasionally as a deterrent. Some composting units come with a plastic base or a wire mesh can be placed under and around the base of the bin to prevent rodents from burrowing under to get in. You can also set traps around the bin to capture or kill these furry pests if nothing else works and it has become a persistent problem. ↑ Top

 

3. What do I do if there are lots of flies in my composter when I open it?

Fruit flies love the sugar found in vegetative food scraps, especially fruit peelings or trimmings. If you take the top off of your bin (holding bin or wormery) and dump your food scraps on top without mixing or burying them into the pile or worm bedding, you will create the perfect environment for a fly hotel. Needless to say, all food scraps need to be incorporated into your compost pile or into the worm bedding so they are not exposed to the surface or top of the pile. If fruit flies are still a problem, then simply leave the lid of the holding bin off or the top of the worm box top open on a sunny day for 2-3 hours. This allows most of them to fly away. Then cover the contents or bedding with wet sheets of newspaper to create an entry barrier and replace the lid or close the top. This will limit access to composting materials and should reduce or eliminate the fruit fly problem.

Keeping a stock of brown leaves, sawdust or other “brown” material next to your compost bin will make it easy for you to cover the food scraps, and will help the composting process.

If the pile is swarming with blue bottle type flies or maggots, there is a good likelihood that meat or other products of animal origin are being added to the pile and/or food scraps are sitting on top of the composting materials. Again, please remember to bury food scraps within composting garden or landscape materials or within the worm bedding. Also, please stop adding food scraps of animal origin. ↑ Top

 

4. What do I do if I find slugs and/or snails in my compost pile?

Slugs and snails like fresh green leafy materials like lettuce. If there are only a few slugs or snails, then don’t worry, they are part of the decomposition process. If there are more than you care for, then simply turn the pile and cover it with wet newspapers or plastic sheeting.

Slugs’ eggs occur in clusters, and look like spherical drops of water. You can remove these as you find them if you like, but don’t confuse them with the valuable yellow eggs of the composting worms! ↑ Top

 

5. Do I need to water my compost pile?

It is important to check the moisture level of your pile on a regular basis. If the pile is dry, composting slows or stops. Be sure that materials are as wet as a wrung out sponge. Remember that composting happens in the thin film of water that surrounds each composting particle, so maintaining adequate moisture is key to optimal composting. Feel the materials in the pile. If it is wet to touch, then fine. If it is too dry and/or dusty, then turn the pile and sprinkle moisture throughout. ↑ Top

 

6. Should my compost pile or system be covered?

In rainy Ireland, covering your pile is a good idea, especially in colder winter months when the pile is less active. Many bins come with lids so no worries there. Open piles or bins can be covered with plastic sheeting, old carpet or plywood to keep rainfall out. In summer months, covering the pile keeps moisture in. As the composting organisms like a moist environment, this is a good thing and promotes thorough decay of materials throughout the bin or pile. However, too wet (waterlogged) and the process will stop working, and the pile may turn foul and smelly. ↑ Top

 

7. Does compost need to be turned?

No, not necessarily. Most holding systems are designed not to be turned. Many bins work by adding materials to the top while harvesting materials out of the bottom. Turning does mix materials and fluff them up to promote passive aeration. Turning also adds air to the pile which can speed up composting. If you cannot turn the pile due to the fact that the opening of the compost bin is too narrow and would like to promote better aeration, simply place a perforated pipe into the middle of the bin before adding materials – the yellow corrugated drainage pipe used on farms is ideal. Alternatively, you can loosen up the material with a garden fork to introduce air into the top layers of fresher materials in a holding bin or you can purchase a spiral compost mixer that can be described as a giant corkscrew to mix things up. ↑ Top

 

8. How do I speed up the composting process?

Follow all of the essentials of composting that can be found in our general home composting brochure. These include chopping things up into smaller pieces, properly balancing of “green” and “brown” materials, turning the pile to add air or fluff it up to encourage passive aeration, and making sure that materials are wet enough to promote optimal composting. ↑ Top

 

9. Should I add worms to my compost bin?

If your composting system is working reasonably well, worms and other decomposers will find their own way in, even if the bin is placed on concrete or tarmac. Adding worms from your garden may not be helpful, as some species of worms need to live underground in soil and will need to escape from your bin or may die in there. Slugs and earthworms make their way to the lid of the compost bin. Don’t worry this is a good sign and they will make their own way back into the material to be composted. ↑ Top

 

10. How long does it take to make compost?

This depends on the system you are using, the type of materials you are trying to compost, and whether or not you are following all of the essentials of composting. In general, holding systems take longer than turning systems. You can expect that any materials you add to a holding system in one gardening season would be ready the following year. If you are composting leaves in a holding system to make leaf mould or making a turf loam topsoil out of sod, then it may take up to two years to complete the composting process. For turning systems, compost can be ready in as little as 8 weeks. For wormeries, compost can be harvested in 6-12 months, often less if the weather has been warm and the worms very active. ↑ Top

 

11. How do I know when my compost is ready?

Use your senses to tell when compost is ready:

  •  Look at it: If the compost is dark in colour and it is hard to recognise the original raw materials- it looks ready
  •  Touch it: If the compost is not hot or warm and has a texture of rich soil, breaks apart easily and is crumby to the touch- it feels ready
  • Smell it: If the compost has a pleasant earthy smell, and it looks and feels ready, then it is ready! If the composting material is hot, smells strong or unpleasant, or you can recognise the raw materials in the pile- then it is not ready to use and will need more time. Just let it rot!

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Mulching and Using Compost

1. How do I use my compost?

2. How does compost affect the acidity of the soil?

3. Do I need to add fertiliser to my garden if I use compost?

4. Can I use pure compost to grow plants?

5. How much compost should I use?

6. What if I have more compost than I can use?

7. Will mulching with wood chips or chavings rob nitrogen from the plants?

 

1. How do I use my compost?

Where there are plants, there is a need for compost. Compost has so many uses you will never run out of ways to use this black gold. Compost can be used as a:

  •  Mulch in annual or perennial planting areas
  •  Topdressing on lawns or turf areas
  •  Soil amendment when preparing the soil for planting turf, annuals, perennials, shrubs or trees
  •  Ingredient in a potting mix of two-thirds garden soil and one-third compost
  •  Ingredient in a seed starting mix of half sand and half compost
  •  Way to make compost tea

To learn more about compost use and specific application guidelines, see our Using Compost Around Your Home factsheet. ↑ Top

 

2. How does compost affect the acidity of the soil?

pH is the measure of a compost’s acidity or alkalinity. The pH scale ranges from 0 (more acidic) to 14 (more alkaline) with a pH of 7 as neutral. Most finished composts have a pH of between 6.5 and 8.5, meaning that in all likelihood, the compost will be slightly alkaline in nature. Every plant has a preferred pH range. The pH of soil can be affected by the pH content of the compost and the quantity used. With many soils in Ireland being slightly acidic, compost has a buffering effect on these soils. As most plants prefer a fairly neutral soil, adding compost is beneficial. Acidic soils tend to limit nutrient availability so adding compost to acidic soils can improve nutrient availability to the plants grown in them. ↑ Top

 

3. Do I need to add fertiliser to my garden if I use compost?

Compost is not a fertiliser, but does contain small amounts of Nitrogen, Potassium and Phosphorous, essential macro nutrients required for vigorous plant growth. Compost is classified as a soil amendment and contains a wide range of micro nutrients such as iron, zinc, cooper, sodium and calcium. It’s like a vitamin pill for the soil. It also contains a wide range of microbes to help balance the ecosystem in the soil. In addition, it contains valuable organic matter, the glue that holds soil together and provides soil with good structure. This organic matter also feeds the ecosystem of life in the soil, slowly releasing nutrients that plants can easily absorb.

Depending on the health of your soil and its nutrient content as well as the type of plants you intend on growing, fertiliser may or may not be necessary. If fertiliser is used, apply it and dig it in at the same time you are adding compost to planting areas. The compost acts as a sponge in the soil holding both water and nutrients in the root zone of your plants. In other words, compost helps keep fertiliser nutrients from leaching out of the soil and keeps them in the soil longer for plants to absorb. ↑ Top

 

4. Can I use pure compost to grow plants?

Certain plants, like potatoes, tomatoes, and pumpkins, may thrive in pure compost, but most will not. Especially sand- or loose soil-loving plants e.g. carrots will struggle in the rich and moist environment of a pure compost growing medium. So better to mix it with soil and/or sand, depending on the needs of your plants, or consult with your local garden centre or gardening experts if unsure. Less can be more – better to be safe than sorry! ↑ Top

 

5. How much compost should I use?

This depends on the soil you have and the types of plants you want to grow. For establishing a new turf area with sod or grass seed, spread 1-2” of compost on top of the existing soil and mix in to a depth of 6-8”. For topdressing existing turf areas, screen the compost so it has a fine texture and spread a quarter to a third of an inch on top. For annual plantings, flowers, herbs or vegetables, add 2-4” on top of the existing soil of the planting area and mix in to a depth of 8-12”. When planting trees or shrubs, place 2-3” in the bottom of each planting hole and mix well with the soil in the bottom. Also add and mix compost into the soil taken out of the hole before placing it back around the root ball of the new plant. Don’t forget to add fertiliser and/or lime at the same time so it can be mixed and added to the soil as well. ↑ Top

 

6. What if I have more compost than I can use?

Most gardeners never have enough compost: they mulch their gardens, add it to planting areas, treat the lawn, feed houseplants, make hanging baskets, fill tubs, etc. So if you cannot use it all, then give it to gardening friends! ↑ Top

 

7. Will mulching with wood chips or shavings rob nitrogen from plants?

This only happens when the wood chips or sawdust get into the soil. Because wood chips or shavings are high in carbon, if they are dug into the soil, they require nitrogen to break down. As there is only a limited amount of nitrogen in the soil, decay of woody material competes with plants that also require nitrogen from the soil to grow. Placed on top of the soil, wood chip or shavings slowly break down drawing nitrogen from the air and release nutrients to the soil below.↑ Top

GrassCycling

1. Will GrassCycling make my lawn look bad?

2. Can grass cuttings damage lawns?

3. Does GrassCycling cause thatch build-up?

4. Is GrassCycling always appropriate?

5. Does GrassCycling spread lawn disease?

6. Does GrassCycling require special equipment?

7. Will I have to spend more time mowing my lawn?

8. Can I fertilise my lawn less often if I GrassCycle?

 

1. Will GrassCycling make my lawn look bad?

No! The key to maintaining a neat appearance is to cut the lawn when it is dry and often enough to produce short grass cuttings that drop down on to the top of the soil and decompose quickly. Follow the one third rule: mow often enough so that no more than one-third of the height of the grass is cut at any one time. If you are worried about people tracking cuttings into your home, try mowing late in the day so the clippings have time to dry and settle overnight. ↑ Top

 

2. Can grass cuttings damage lawns?

No! Clipping are actually a benefit to your law. The clippings fall to the surface of the soil and decompose, releasing valuable nutrients and supplying organic matter to the soil. If you allow the grass to grow too long between cuttings, the thick patches of mowed cuttings can clump and suffocate your lawn in those areas. This can be remedied by gradually reducing your lawn back to its proper height over a period of two or three mowings, rather than scalping it back in one mowing. ↑ Top

 

3. Does GrassCyclingcause thatch buildup?

No! Cuttings and thatch are not connected. Thatch results from the abnormally fast growth of roots and stems and is caused by improper fertilisation and watering. Thatch can build up over time. Periodically it needs to be thinned out by raking or with the use of an aerator. Over fertilisation, fertilising a cool turf variety in the summer, short shallow watering, and growing grass on poor, heavy and compacted soil can each encourage thatching. ↑ Top

 

4. Is GrassCycling always appropriate?

No! GrassCycling does not work in every situation. You may need to collect your cuttings in a number of instances including: when the lawn is wet, more than one inch is cut, the lawn is diseased, during cool or prolonged wet weather or mower breakdowns. Also, GrassCycling may not be appropriate during cooler times of the year. In early spring and late autumn, cool temperatures and high rainfall may slow decomposition. When cuttings need to be collected, they can be added to your composting system. Be sure to balance them with some brown materials. ↑ Top

 

5. Does GrassCycling spread lawn disease?

No! Improper watering and fertilising are the primary culprits that cause lawn disease. The spores that cause grass disease are present whether the cuttings are collected or not- if an environment for disease is present, it will occur whether cuttings are left on the lawn or not. ↑ Top

 

6. Does GrassCycling require special equipment?

No! In most cases you can use your existing mower to GrassCycle. Refer to your owner’s manual or contact your local lawnmower dealer to learn how to GrassCycle with your mower. You may need to purchase a retrofit kit, and your mower dealer can assist you with selecting the correct one and getting it installed if necessary. ↑ Top

 

7. Will I have to spend more time mowing my lawn?

No! You may have to mow your lawn more often, but a study has shown that people who GrassCycle actually reduce the time they spend on lawn care overall as they save time by not emptying the grass-catcher bag, raking the grass, composting it or carrying it to the bin to be collected. ↑ Top

 

8. Can I fertilise my lawn less often if I GrassCycle?

Yes! Studies indicate that GrassCycling reduces the need for fertilising by at least 25%, since the grass cuttings themselves have nutrients. Some people who GrassCycle don’t use commercial fertiliser at all. It just depends on how nice and green you want your lawn to be. Most people who GrassCycle reduce the amount of fertiliser used or frequency of application. ↑ Top