Compost heap covered in snow

Winter Composting: What to compost

In the summer I can haul several wheelbarrows of weeds in a day to my compost heap, rapidly building up its size. But things are very different in the garden in winter. Having just come back from a pleasurable hour in the garden, I’ve only managed to pull up a small bucketful of weeds and trim some old brassica leaves – a far cry from my summer haul.

But that doesn’t mean there’s nothing to compost. In fact, with some imagination, we can still find tons of things to compost.

So here’s some suggestions, which vary from the mundane to the weird. Hopefully, this will help you come up with your own ideas – after all, if it’s been recently alive, it’s probably compostable!

Hair

“You want what?” My hairdresser was rather surprised when I ran into her in the pub and requested a sackful of hair.

But about 15% of human hair consists of nitrogen, making it a particular rich source for the composter. In fact, it’s incredible to think about the amount of nitrogen that is wasted in an era where expensive, resource heavy fertilisers are produced in huge quantities. So next time you are in your hairdresser, consider asking her to keep a sack of hair back for you.

Nail clippings can also be composted, but are unlikely to provide the volume you need.

Urine

Every year you produce around 135 gallons of urine. Each time you flush it down, you waste up to 14 litres of water, an increasingly precious resource.

But pee is rich in nitrogen, and studies have shown that compost with added urine performs better than regular compost, helping prevent the accumulation of salts and balancing out the slower releasing nutrients found in compost.

With just the occasional pee, you can easily boost the nitrogen level of your compost. Being high in nitrogen, it’s best to mix it with a brown such as shredded paper. Or you could follow the National Trust’s example and put a straw bale outside to pee on, adding it to your compost at a later stage.

Leaves

Raking up Fall Leaves.
Photo credit: Ken Fukunaga

There’s still tonnes of leaves lying around in huge drifts in early winter. It can literally take minutes to pack up several sacks of leaves.

Do note that leaves are high in lignins, which means it can take them a long time to break down, and when they are fresh they may not be the best composting material. Many people use these to make leaf-mould, leaving them in a bin or a wire enclosure for up to two years while they slowly decompose.

But an alternative is to break them up with a lawnmower, and mix them with a green such as urine to achieve a better carbon:nitrogen ratio. If it’s too snowy or wet to break them up, consider stockpiling them for future use.

Hedge trimmings

Hedge trimmings, especially in winter, are both a brown (high carbon material) and full of lignin. But if you have a shredder, you can cut these up into a much more digestible form for your compost pile.

Food waste

Our gardens may stop growing in winter, but we don’t stop eating. I’m currently adding several kilos of food waste a week to my hot compost bin, combining cooked waste, vegetable peelings and waste collected from two waste bins I have put in my office. These contain a lot of coffee grounds and tea bags, which are a great, high nitrogen addition for the compost pile. Coffee grounds can also be collected from local cafes.

Do note that cooked food waste should only be processed in a system that is designed for it, such as an insulated, enclosed bin that is already operating at a high temperatures or a fermenting system like the Bokashi bin.

Animal bedding

The stables where my son goes for riding lessons has a manure heap which is about 16 foot high. Like many stables, rather than being a resource for them, manure is a nuisance they would happily get rid of.

In fact, another stables near me used to have a sign saying free manure. Even better, the manure is often mixed with straw, giving you both high nitrogen and high carbon materials in one source.

One word of warning with manure, though. A lot of hay nowadays is treated with a pesticide, Aminopyralid, which is not broken down by animals’ digestive systems. I found this out to my cost when I had a large trailer load delivered to my garden last year. Everything I put it on stopped growing for several months. The pesticide does break down eventually when in contact with soil, but if you do use manure to make compost, it’s worth testing it first by planting some seeds in it to ensure it is not problematic. Broad beans and clover are supposed to be particularly susceptible to Aminopyralid, so make good testing plants.

(As a side note, many shop-bought composts, including ‘organic’ compost, contain traces of aminopyralid, which is another great reason for making your own compost.)

I am fortunate enough to have chickens, which not only supply us with far more eggs than we can eat, they also provide us with chicken manure. This is a fantastic activator, and when I recently added it to my insulated compost bin the temperature shot up by almost 15 degrees. I do get the straw I use from a trusted local source.

(A chicken farmer I knew always advised that chicken manure should be left several years before being used.The chicken bedding I use, though, is only a small part of my total compost heap.)

You may not have chickens, but there is a good chance you will know someone who has rabbits, hamsters or guinea pigs. Even if there is not much, what you do get can often help accelerate your compost.

Dog and Cat Droppings

According to the Alaskan Dog study, the average dog produces 274 pounds a year in droppings. While I am not suggesting you go around collecting other people’s dog droppings, if you do have a dog, composting its droppings is far better for the environment than placing it in a plastic bag or allowing the run off to pollute the earth and ground water.

However, dog and cat droppings should only be composted if you have consistently high temperatures in your compost pile, as the droppings can carry pathogens and worms. It’s also best to avoid using droppings from cats and dogs which are sick.

Garden material

Despite the fall off in growth in winter, there’s usually something to compost in winter, especially if the winter is mild. I am regularly pulling old and nibbled leaves from my kale, spinach and Brussel Sprout plants. When they fall to the ground they can encourage slugs, and keeping my compost bin going is a great motivation to keep them neat and tidy. A quick one-minute chop with a pair of garden shears reduces the size of the leaves and helps the microorganisms in the heap digest them.

In the mild winter we are currently having, there are still some weeds growing. Pull these up by some roots and they inevitably come up with some high carbon soil to balance the nitrogen in the greens.

Wood

Wood takes a long time to break down, but if you have a wood chipper, you can produce compostable material, although being high in lignins, it will take a while to break down. You can also keep twigs back to form the base of future compost heaps, or, if you have a lot of wood you could consider creating a Hügelkultur raised bed.

Seaweed

Shreds of seaweed on white sand.

There’s a reason why sea-wood fertiliser is sold in shops – it’s packed full of good stuff, including nitrogen, potassium, phosphate and magnesium as well as hormones that encourage plant growth. There’s also no need to wash the seaweed to get rid of the salt – the Royal Horticultural Society advises that there’s enough salt to deter slugs, but not enough to damage the soil.

With storms blowing up mountains of the stuff onto the beach, winter is a great time to collect seaweed. Two or three times a year, I park up by a nearby beach and haul bags of the stuff back to my car.

You don’t even need to add it to your compost, as seaweed can be dug directly into the ground. I follow a no-dig system, so I tend to lay it around tender plants. This enriches the soil while the salt deters slugs.

One negative – there do always seem to be a lot of flies in seaweed, so I always leave the car windows wide open when driving back home to try and get rid of them.

Shredded paper and cardboard

Pile of cardboard.

I collect a least a sack of shredded paper from my office per week, and it’s a fantastic addition to the compost heap. Not only does it balance out green material, the small size of the shredded paper means it’s easily digested by compost bacteria and it does a great job of absorbing excess liquid.

Even if you don’t have any friendly offices near you, chances are you get a ton of mail and bills. If so, it might be worth getting a small shredder. There’s a definite joy to turning unpleasant bills into valuable composting material.

The same goes for cardboard, and as Christmas approaches most people have more cardboard than usual. You can use cardboard in strips between green materials in compost materials, but it works better if you rip up the cardboard and put it into the compost. It’s worth ripping up off any tape if you can, but if you can’t, you can always pick it out from the compost when it is finished.

Thinking ahead to the spring…

When there’s not much to do in the garden in winter, you can find yourself with extra time to get out and collect materials for the garden.

But one thing to bear in mind is that in the coming spring and summer you’ll have a lot of greens (high nitrogen materials) to compost. In fact, it can be a challenge to find enough browns (high carbon materials) to balance out the greens and obtain a good carbon:nitrogen ratio.

So when collecting browns in the winter, it’s a great idea to stockpile some of them for future mixing. Then, as the day finally get longer and the shoots of spring pop up, you’ll be primed and ready to have a balanced compost pile to enrich your soil in the months ahead.