Compost From Kitchen Scraps: The Perpetual Compost Tower

Direct answer: A compost tower is a vertical, open-bottomed cylinder — hardware cloth or a stack of perforated bins — filled in layers with kitchen scraps and carbon material. Worms and microbes move in from the soil below, and you harvest finished compost from the bottom while adding to the top. Minimum size is about 18 inches across and 30 inches tall.

How the tower works

It is a continuous vertical flow: fresh material at the top, active decomposition in the middle, finished compost at the bottom. Because it sits on soil, worms and soil life colonise it without inoculation. Because it is vertical, it takes a fraction of the footprint of a traditional pile.

What goes in, what stays out

The working ratio is roughly 2–3 parts carbon (browns) to 1 part nitrogen (greens) by volume. Kitchen scraps are wet and nitrogen-rich, so every bucket of scraps needs a bucket and a half of shredded cardboard, leaves, or straw.

Siting and sizing

Put the tower in part shade — full sun dries it out and bakes the kitchen scraps — on soil rather than concrete, and within easy carrying distance of the kitchen door. Avoid the property line: even a well-managed pile can draw flies in summer, and neighbours notice.

An 18–24 inch square by 30–36 inches tall handles the scraps of a two-to-four-person household. Two towers side by side let one finish while the other fills. A single tower that is emptied and refilled every few weeks works too, but the compost is less finished.

Building steps

1. Choose a spot in part shade, on soil, near the kitchen but away from the neighbour's fence.
2. Drive four stakes in a 18–24 inch square and wrap with 1/2-inch hardware cloth, 30–36 inches tall.
3. Line the bottom with 4 inches of coarse browns — twigs, straw — for airflow.
4. Add alternating layers: scraps, then carbon, then a sprinkle of soil or finished compost.
5. Cover with a lid or a thick layer of browns to keep rain out and flies down.
6. Every 1–2 weeks, lift the cylinder, fork the contents back in, and harvest finished compost from the bottom.

A two-tower rotation works better than one: fill one while the other finishes.

When you have more scraps than space

Two towers and a household of four will keep up with vegetable scraps, coffee grounds, and eggshells. They will not keep up with a juicing habit, a garden cleanup, or a neighbour's grass clippings. For surplus:

• Bokashi bin indoors — ferments everything including meat and dairy in a sealed bucket, then gets buried or added to the tower. Two weeks per batch.
• Second tower — cheapest capacity increase, and it gives you a finished batch while the other fills.
• Sheet compost — spread surplus greens between beds under a layer of cardboard and mulch; it breaks down in place.
• Neighbour arrangement — a shared tower with a household that gardens is often the simplest answer.

Troubleshooting smells and pests

• Smell: too wet or too much nitrogen. Add carbon, turn, and cover.
• Flies: exposed food scraps. Bury every addition under 2 inches of browns.
• Rodents: usually meat, dairy, or grain in the pile. Remove them and set the tower on hardware cloth.
• Nothing breaking down: too dry or too cold. Water to damp-sponge consistency and turn.
• Slow in winter: normal. Keep adding carbon and let it finish in spring.

Frequently asked questions

Use the compost in raised beds or in-ground beds, and see the book review for the soil chapter this supports.

Frequently asked questions

Keep reading

• Raised Beds vs In-Ground Garden on a Small Lot
• How to Plan a Quarter-Acre Homestead