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How to Fix Slimy Compost and Stop It From Turning to Sludge

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Rotational composter

Rotational composter

Why Composting Is Good

When organic waste like vegetable peelings and food leftovers are put into general waste and are sent to landfills, they do not properly biodegrade and create gases that are harmful to the planet. Some authorities charge for waste collected by weight, so anything you can do to reduce the amount of stuff you throw away will save you money, be good for the environment and provide you with good quality free compost for the garden or indoor plants.

Home composting reduces the amount of waste going to landfills, stops your kitchen bin from smelling and creates some of the best and most nutritious material to use in your home and garden. Homemade compost is far richer in nutrients than the 'compost' which is sold at garden centers.

An example of what you can put in your compost from the kitchen

An example of what you can put in your compost from the kitchen

The Art of Composting

Why Your Compost May Be Too Wet

Making good compost from kitchen and garden waste does take some practice and many people find they end up with a slimy, smelling sludge. This is usually due to the mixture being too wet as most organic waste has a high water content. A lack of air can also create a poor compost, which is why you should add scrunched-up newspaper and dry twigs/sticks to avoid the compost becoming too compacted.

When composting we have green and brown waste.

Green waste is vegetable peelings, tea bags, coffee grindings, food leftovers, eggshells, old flowers, fresh grass clippings and plant waste.

Brown waste is paper, cardboard, dry leaves, dry grass clippings, and twigs/sticks.

How to Dry Out Compost

The ideal mixture should be moist but not wet and have an earthy odor. If it is too wet you should add drier 'brown' material and use a garden fork to mix it up regularly and to make sure it is not too compacted.

Here I have added dry garden waste from purning and torn up cardboard which I will then mix in with a garden fork.

Here I have added dry garden waste from purning and torn up cardboard which I will then mix in with a garden fork.

Wet vs. Dry

The problem most people have is that their compost is too wet and it becomes very slimy, light coloured and smells a bit like excrement. You can see from the picture that mine is getting better and turning much darker but I still need to add some dry twigs and torn up cardboard and mix it in with a garden fork. If the weather is good and rain is unlikely I leave the lid off for a day or two until it dries out a bit.

Why Your Compost May Be Too Dry

If your compost is too dry then it will not start to rot down properly, you can add a little water to increase the moisture level. Some people suggest urine, which helps to get the process started! I enjoy gardening but am not that hardcore and I'm sure my neighbors wouldn't be too happy to witness this practice while entertaining guests and their children in the adjacent gardens!

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Dry Brown Material

After a session of garden maintenance, I put the majority of what I have cleared into a pile where it can dry naturally in the sun and provides a good source of dry brown material. Anything including branches, twigs, leaves and grass cuttings will work. Old cardboard (brown only without any print) and old newspapers are also excellent sources of dry material.

It should be noted that some weeds, especially invasive varieties such as Japanese Knotweed, should never be put into a compost pile as they will continue growing and spread. They should either be burned or bagged up and taken to the dump.


Good-Looking Compost!

Here you can see the compost is working well, still a little wet and with some eggshells and sticks that have not rotted down yet. They take the most amount of time to decompose, but most of the material has turned to compost. In a few months, it should be ready to use. The compost should be turned regularly with a garden fork to mix it up, this will prevent it from becoming too compacted in places and allow air to move around and will also encourage worms.

When using a compost bin with a lid it is called 'hot' composting and this means the mixture will actually get warm and you can see steam rising from it on cold days—this is an indication the process is working well.


What Not to Put in Your Compost

Meat (including bones) and dairy waste should not be put into your compost (except egg shells) as it can attract pests and harmful bacteria may remain which can be dangerous if you are using the compost to grow fruit and vegetables.

It is also recommended that you do not put anything in your compost which is high in citric acid, such as lemons and limes. Animal waste and the contents of 'litter trays' should not be added and large amounts of oils, fats or grease should be kept out of your compost bin/pile too.

Obviously, any nonorganic material should not be added such as plastic, painted or varnished wood, metal or chemicals.

How to 'Turn' Compost

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.


Ruth A Carroll on August 28, 2020:

I am new at composting yesterday i turned my compost and it was very steamy today i looked at it and it was slimy and smelled what can i do

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