Where there’s mulch, there’s brass – discovering the riches of home composting

Where there’s mulch, there’s brass – discovering the riches of home composting

Homemade compost is often referred to as ‘black gold’ by gardeners. It’s chock full of nutrients and makes an excellent fertiliser. It’s a valuable addition to any soil, keeping it healthy and full of the goodness that plants need to thrive. It also works wonders in soil that isn’t particularly welcoming. Clay soil, for example, can become like cement in dry weather and a quagmire in prolonged wet. Very sandy soil, on the other hand, can drain so efficiently that much of the fertility is sucked out. Compost improves the structure of both, helping to resolve these problems.

It also encourages invertebrates such as worms, which in their turn improve the soil themselves. And a flourishing population of soil invertebrates encourages the birds and other wildlife which feed on them.

Making your own is the most environmentally friendly way of reusing food and garden waste. It might seem easier to simply get your local authority to take it away, but the transport involved adds to your carbon footprint and some councils don’t take food waste. What’s more, you’re turning your back on an essential garden resource and frequently paying for the privilege!

What happens during the composting process?

Bacteria, fungi and invertebrates such as worms and centipedes break down organic matter. They need the right balance of warmth, moisture and oxygen to do this.

What goes into the mix?

A combination of green (leafy, nitrogen-rich) and brown (woody, carbon-rich) material. Too much green material and you end up with a sticky mass or at worst a sort of gloopy sludge. Too much brown and it will take forever to break down.

Opinion differs among composting gurus as to the ‘ideal’ mix. Some recommend 50% brown to 50% green matter, others recommend proportions of 4:1 brown to green. But in fact there is no ‘ideal’ mix. What will work depends partly on the specific materials that are in there (such as the amount of grass clippings making up the green material) and the conditions – the amounts of heat, air and water. So it’s not an exact science and the process is not completely within your control anyway. It’s best to aim for between 25-50% green matter with brown making up the rest.

What you should avoid though is allowing one particular material to dominate. Large quantities of grass clippings, for example, will simply rot down to a slimy mess.

Green material includes:

Grass clippings, annual weeds and other soft, leafy plants, most fruit and vegetable kitchen waste, coffee grounds and teabags. (If you’re putting teabags in however, check they don’t contain plastic. The packet should give you this information but if in doubt, leave them out.)

Brown material includes:

Woody prunings and hedge trimmings, autumnal fallen leaves, cardboard and most paper and straw.

You can also add egg shells although these take quite some time to break down. Crushing them finely will help.

DON’T add:

• Diseased plant material or perennial weeds – home compost heaps and bins are too small to get hot enough to destroy pathogens and tough weeds
• Cooked food or animal products (meat, fish and dairy) – these attract unwelcome rodent visitors!
• Citrus – it’s too acidic
• Gloss or colour printed paper
• Animal faeces

For more information on recycling some of these:

http://www.lesswaste.org.uk/2019/12/18/dealing-with-those-harder-to-compost-items

Composting tips:

• It’s best to mix grass clippings and kitchen waste in with woody material – such as paper or cardboard – as you add it. This is because on their own they tend to clump together, excluding air.
• Crumple up paper, tear egg boxes in half and leave loo roll centres intact. This will help to aerate your compost. Shred or chop up woody stems to help them break down more quickly.

Bin or heap?

This depends in part on how much space you have. Compost heaps do tend to wander and are difficult to contain, especially when you turn them, so bins are better in a small space. Compost bins also retain more warmth and moisture so their contents break down more quickly.

Compost bins should stand on the soil and be open at the bottom. This allows essential airflow. It also opens the door to worms and other invertebrates which speed up the process. If you’re worried about rats, chicken wire across the bottom should help to keep them out.

(Wildlife safety alert: If you have a heap, be aware that it may be a nesting or hibernating spot for all sorts of creatures. Hedgehogs, bumblebees, slow worms, grass snakes and shield bugs all use them as a safe haven. So when you turn your compost you risk disturbing them. Hibernation usually takes place from October to March so avoiding disturbance between September and April should be more animal-friendly. Wildlife gardener Kate Bradbury advises only turning in April; this is when hibernation ends but nesting hasn’t yet begun. Bear in mind though that this will slow down the composting process.

Wildlife hidey holes are much less likely to be found in compost bins. However it does happen – bumblebees have been discovered nesting within. So keep an eye out for uninvited guests and change what you do accordingly. There’s some advice on how to manage this situation here: https://www.buzzaboutbees.net/can-i-remove-a-bumble-bee-nest-from-a-compost-bin )

Sun vs. shade

Some composters recommend a sunny spot, others recommend shade. Again, there are several factors at play and you can’t control them all.

Heat speeds up the process but the bacteria and fungi that do the work can be hampered or even destroyed by extremes of temperature. So placing your bin in full sun may be counterproductive during a blazing summer. It’s hard to predict what the weather has in store for us but as the last couple of summers have been such scorchers, your safest bet is probably to site a bin somewhere that gets sun for part, but not all, of the day.

Maintenance

Turn regularly with a fork. This ensures that green and brown and decomposing and new material are well mixed together. It also helps aerate and speed up the process. Lack of oxygen can lead to a smelly bin too! Advice on how often compost should be turned varies from every 3-4 days to every 4-5 weeks. The RHS suggests once a month, which seems practical and not too demanding!

Keep your compost moist in very dry weather. If it does dry out, water it lightly. It should feel just damp but definitely not soggy.

In winter close the lid to keep the heat in. In a hot summer open the lid and place hessian over the compost surface. This will keep retain heat but allow moisture in too so that compost doesn’t dry out too much.

You’ll find a helpful video here: https://www.gardenersworld.com/how-to/grow-plants/dealing-with-composting-problems/

You may find it useful to add compost activator if the contents of your bin or pile seem to be slow to break down. Most are high in nitrogen, which helps break down woody material.

How long does it take?

Usually between six months and two years, depending on the conditions. You’ll know when it’s ready by the look and feel of it. Properly broken-down compost is dark and crumbly. You may notice the rich, earthy smell that you get in damp, wooded areas, especially in autumn. Don’t worry if there are still a few twigs in there. These can be put into the next batch of compost, added to your mulch or dug in where they will continue to decompose.

Trouble-shooting

Dry and fibrous plant matter that isn’t rotting down: too much brown material and possibly too little moisture. Add more green material or compost accelerator.

Slimy and smelly compost: too much green material, too little air and too much water. Add more brown material and turn the compost.

Flies: Cover kitchen waste with brown material, check moisture levels aren’t too high.

https://www.rhs.org.uk/soil-composts-mulches/composting

Limitations

Homemade compost is a marvellous thing but it doesn’t meet every gardening need. It’s often too coarse and high in nutrients for reliable seed germination. And even if your seeds do sprout, your compost may not have become hot enough to kill off the pathogens, such as damping off, that seeds and seedlings sometimes fall victim to. Specially formulated peat-free seed compost is better suited for seed-sowing and growing.

A compost bin doesn’t take up much space and the results of your labour will have many uses – mulching, backfilling, potting and giving your soil a boost. Making your own is an art as well as a science and, perhaps because of this, it can become a hobby that provides nearly as much enjoyment as gardening itself. I’ve known several people who begin composting as a practical solution and who, much to their surprise, end up becoming enthralled by it. So why not give it a go?