Composting Tips for Kitchen Waste and Cardboard

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Composting tips for kitchen waste and cardboard

One of the benefits of staying home for Covid control is more time for gardening, and perhaps more time for composting, too. Cooking at home more often produces greater quantities of compostable food waste, and in many areas suspended recycling services have led to unsightly stockpiles of cardboard that can be dealt with in part via composting. There also are many new gardeners among us who want to start composting, which can be confusing at first. Here’s a roundup of composting tips of special relevance during the Covid crisis.

With trench composting, kitchen waste is buried in marked garden beds

Trench Composting Kitchen Waste

Isn’t it amazing how fast your countertop compost pail fills up these days? Between continuous home cooking and garden veggies that need trimming and cleaning, your kitchen waste stream will soon turn into a gusher.

Here you have many choices, including the age-old method of simply burying kitchen waste in the garden, called trench composting. Fruit and vegetable trimmings, coffee grounds, used paper napkins and icky meatless things from the back of the fridge can go straight into the ground provided they are covered by four inches (10cm) of soil. When trench composting kitchen waste, most gardeners work their way down a row or bed, marking the last buried cache with a stake. The drawback to trench composting is that you must risk muddy shoes every time you need to dump your compost pail, so you also might want to keep a stationary composter in an accessible spot.

Earthworms and other tunnelling creatures improve the soil under and around a stationary composter

Stationary Composters Improve Soil

Stationary compost containers that sit on the ground hide kitchen and garden waste from view, retain moisture and warmth to promote decomposition, and attract earthworms, tunneling insects and assorted mini-molluscs to the composter’s footprint. If you are expanding your garden, locate a stationary composter where you plan break new ground to make use of its passive soil improvement properties.

You can buy inexpensive stationary composters made from recycled plastic, or make your own by removing the bottom from an old trash can. Or, take up box composting by using a big cardboard box as a single-season stationary composter. As you fill the box, put slow-rotting rough stuff around the edges, with kitchen waste and pulled weeds toward the centre. When the box is full, start another one. Box composting also smothers weeds and grasses, so it’s a good method to try in places you plan to bring into cultivation.

You can compost kitchen waste indoors with the help of composting worms

Composting with Worms

The quietest, most odor-free pets I ever had were earthworms that lived in a plastic storage bin in my basement. They loved tattered lettuce leaves and leftover rice and pasta, which they turned into rich vermicompost for my garden. I kept worms as an enjoyable hobby, but if the only place you have to compost is your storage room, try composting with worms. A plastic bin with its sides well perforated with air holes makes a good container, and you can use shredded cardboard or newspapers for bedding.

Earthworms captured outdoors will do an adequate job of turning kitchen waste into compost, but it’s best to get some composting worms, also known as red wigglers (Eisenia foetida). These guys thrive at cool room temperatures and multiply rapidly when conditions are good. When you want to harvest vermicompost, open the bin and place a pile of worm-laden material on the inside of the lid. Wait ten minutes or so, and the worms will move the middle of the pile where they can be gathered and returned to the bin.

Cardboard boxes are easiest to flatten when wet. They then can be composted or used as mulch in ornamental beds

Composting Coloured Cardboard

In 2017 I wrote about the ways I deploy cardboard in the vegetable garden, mostly by using clean, undyed cardboard shipping boxes to smother weeds between widely spaced plants. But now it’s Covid time, my local recycling program has been suspended, and I’m stuck with either composting my cereal and dog biscuit boxes or trashing them.

Two composting methods are useful for what I think of as nuisance cardboard. You can use the flattened boxes as a sheet mulch in flowerbeds, which is then covered with enough wood chips or other mulch to hide the cardboard from view. Or, simply layer the wet cardboard into an outdoor heap of coarse material, keep it as moist as you can, and let time do its thing. Either way, save yourself work and aggravation by thoroughly dampening the boxes as you prep them for compost duty, or simply leave them out in the rain. Water melts glue and lifts tape like magic.

Is Covid composting a thing at your house? How does sheltering-in-place translate into composting-in-place for you? Please share your story below.

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Show Comments


"Good idea on composting cardboard. How long does it take to breakdown if the cardboard is put in a pile? Is there a limit on the height of the pile? With all the online shopping the boxes really pile up. "
Mark Hausammann on Sunday 24 May 2020

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