Why Every Gardener Should Compost
Compost is often called "black gold" by gardeners — and for good reason. This dark, crumbly, earthy-smelling material improves soil structure, adds a broad spectrum of nutrients, boosts microbial activity, and helps soil retain moisture. Best of all, you can make it for free using materials that would otherwise go to waste.
Composting is also one of the most sustainable things a home gardener can do. Organic waste sent to landfill generates methane — a potent greenhouse gas. Composting at home diverts that waste into a genuinely useful resource.
Understanding the Basics: Browns, Greens, and Balance
Successful composting relies on balancing two types of materials:
Greens (Nitrogen-Rich Materials)
These are moist, often fresh materials that provide nitrogen — the fuel for microbial activity that breaks down compost:
- Fruit and vegetable kitchen scraps
- Fresh grass clippings
- Coffee grounds and tea leaves
- Fresh plant trimmings and weeds (without seeds)
Browns (Carbon-Rich Materials)
These provide carbon, which gives microorganisms energy and helps create a well-aerated structure:
- Dry autumn leaves
- Cardboard and paper (torn into pieces)
- Straw and hay
- Woodchip and sawdust (untreated)
- Dry plant stems
The ideal ratio is roughly 3 parts browns to 1 part greens by volume. Too many greens and your pile becomes slimy and smelly. Too many browns and decomposition slows dramatically.
What NOT to Compost
- Meat, fish, and bones (attract pests)
- Dairy products and oils
- Diseased plant material
- Weeds that have gone to seed
- Dog or cat faeces
- Glossy magazine paper
- Treated or painted wood
Step-by-Step: Building Your First Compost Pile
Step 1: Choose Your Composting Method
You have several options depending on space and budget:
- Open pile — Simple heap in a corner of the garden. Free but can look untidy.
- Wooden bin — Good airflow; easy to build from pallets. Ideal for most home gardens.
- Plastic compost bin — Neat, pest-resistant, retains heat well. Good for smaller gardens.
- Tumbler — Enclosed rotating drum. Faster and neater, but more expensive.
Step 2: Choose Your Location
Place your compost bin or pile in a partially shaded spot on bare soil (not concrete), so worms and beneficial organisms can access it from below. Make sure it's reasonably accessible year-round.
Step 3: Layer Your Materials
- Start with a 10cm layer of coarse browns (twigs, woodchip) for airflow at the base
- Add a layer of greens
- Cover with a layer of browns
- Continue alternating layers
- Water lightly if the pile feels dry
Step 4: Maintain the Pile
Compost needs three things to work: moisture, air, and the right balance of materials. Your pile should feel as damp as a wrung-out sponge. Turn the pile every 2–4 weeks using a garden fork to introduce oxygen and speed decomposition.
Step 5: Know When It's Ready
Finished compost is dark brown, crumbly, and smells like forest soil — not rotting food. It typically takes 3–6 months in an active pile, or up to 12 months in a passive pile. You won't recognise the original materials anymore.
Troubleshooting Common Compost Problems
| Problem | Likely Cause | Solution |
|---|---|---|
| Bad smell (rotten egg) | Too wet / too many greens | Add browns, turn the pile |
| Not decomposing | Too dry / too many browns | Add water and greens, turn pile |
| Pest activity | Food scraps exposed | Bury scraps in the centre; use a sealed bin |
| Pile not heating up | Too small / unbalanced | Aim for at least 1m³; adjust greens ratio |
How to Use Finished Compost
Once your compost is ready, you can use it as a soil amendment (dig 5–10cm into beds before planting), a mulch (spread 3–5cm on the surface), or a potting mix ingredient (blend with loam and grit for containers). A single well-managed compost bin can produce enough amendment to significantly enrich your entire garden over time.