How to Make Compost: The Complete Guide to Black Gold for Your Garden

Compost transforms kitchen and yard waste into the single best soil amendment—improves structure, moisture retention, nutrient availability, and disease resistance. It's free, easy, and your plants will show the difference.

What Goes In (Greens = Nitrogen, Browns = Carbon)

• Greens: Vegetable/fruit scraps (no carrot tops—attract carrot fly), coffee grounds, tea bags, fresh grass clippings, green weeds (no seeds/roots of perennials like bindweed, dandelion, dock).
• Browns: Dry leaves, straw, shredded newspaper/cardboard/egg cartons, spent potting mix, woody prunings (chipped small).

What Stays Out

• Meat, dairy, oils, cooked food (vermin, odor)
• Diseased plants, seeding weeds, invasive roots
• Pet waste, glossy paper, treated wood

Build a Bin (or Buy)

DIY double-bay from pallets/decking boards: 4 posts (1m), slotted front posts for removable boards, 5mm gaps for airflow. Front boards slide out for turning/harvesting. On bare soil for worm access.

Credit: Alex Mckay

The Process

1. Layer greens and browns roughly 1:2 by volume.
2. Keep moist as a wrung sponge.
3. Turn occasionally (or let static pile age longer).
4. Spring: skim unrotted top layer, harvest dark crumbly compost below.
5. Return unrotted material to base for next cycle.

Troubleshooting

• Smelly: Too wet, too many greens. Add browns, turn.
• Slow: Too dry, too woody. Water, add greens, chop finer.
• Flies: Bury food scraps under browns.

Using Your Compost

• Trench for heavy feeders (runner beans, tomatoes)
• Dig into veg beds
• Mulch flower beds
• Greenhouse tomato beds
• Seed-starting mix component

Happy compost smells earthy, never rotten. Let it age naturally—accelerators are unnecessary. The worms do the work.