Composting Explained: What to Compost, What to Avoid & How to Do It Right

The Ideal Compost Ratio: How to Balance Greens and Browns

Getting the ideal compost ratio is really about balance between greens and browns, and a common guideline for successful composting is using roughly equal amounts by volume of green and brown materials. There’s no exact rule this is a learning process, and with experience, each small correction improves the compost pile more than strict measurements ever could.

• If the pile smells unpleasant and feels slimy, it usually means too many greens

• Adding dry leaves, shredded cardboard, or straw often solves the problem

• A slow, dry, inactive heap benefits from lightly moistening to help restart decomposition

• Maintaining the right balance ensures faster breakdown, fewer pests, better airflow, and higher-quality finished compost 

• Maintaining the right balance is also one of the easiest ways to speed up your composting process naturally.

Items You Can Safely Add to Your Compost Bin

Kitchen Waste Suitable for Composting

From daily kitchen habits, I’ve learned that kitchen waste is one of the most valuable compost inputs when it is truly suitable for composting and used correctly. Uncooked, plant-based scraps decompose easily and enrich the pile with essential nutrients, making them ideal for consistent, trouble-free composting.

Kitchen waste you can add:

• Fruit peels and cores

• Vegetable trimmings

• Coffee grounds with paper filters

• Loose tea leaves and compostable bags

• Crushed eggshells, washed and dried for faster breakdown

To keep things balanced, I avoid adding large quantities of one type at a time; steady mixing with dry browns prevents clumping and unwanted odours before they become an issue.

Garden Waste That Improves Compost Quality

From routine garden maintenance, I’ve found that garden waste consistently improves compost quality because it makes a significant portion of compost materials, especially during pruning and active growing seasons.

Garden waste that works best:

• Grass cuttings mixed with browns

• Young weeds without seeds

• Spent annual plants

• Soft green prunings

• Fallen leaves and chopped hedge clippings

By blending in tougher plant material that decompose slowly, you provide structure and build long-lasting organic matter, resulting in finished compost that’s reliable and easy to work into soil.

Animal Manure and Natural Additions

From years of field and garden composting, I’ve learned that animal manure and natural additions can significantly strengthen compost when chosen carefully and applied with restraint.

Manures that work well:

• Herbivorous animals provide valuable compost ingredient sources

• Properly managed, safe, compostable manures include cow, horse, sheep, goat, and poultry

• Best used sparingly to prevent nutrient overload

• Understanding the difference between manure and fertilizers helps prevent overuse and nutrient imbalance in compost.

Other natural additions:

• Small amounts of wood ash (adds potassium, avoid excess)

• Hair and nail clippings

• Natural fibres like cotton, wool, and jute

These materials break down slowly, yet steadily contribute trace nutrients and stable organic matter, enhancing compost depth and resilience over time.

Composting Urine: A Scientific Perspective

From a scientific perspective, composting urine, especially human urine, works as a rich nitrogen source and an effective compost activator when handled responsibly within controlled systems. I’ve used it during low-activity phases to reliably support microbial activity without destabilizing the pile.

Best practices for safe use:

• Always diluted and safely applied

• Diluting at a ratio of approximately 20 parts water to 1 part

• Applying directly to the heap, not to plants

• Using it occasionally, rather than frequently

When managed correctly, this dilution provides nutrients without overwhelming the pile or creating odours, which is essential for success and particularly useful where nitrogen-rich materials are limited.

Items That Should Not Be Composting at Home

Through experience, I’ve learned that certain items simply should not be added to composting at home, even if they appear natural. Some materials, although biodegradable, are unsuitable due to health, hygiene, and pest risks, so I consistently avoid composting them to protect the integrity of the compost.

• Meat, fish, dairy products, and cooked food, unless using sealed, hot composting systems

• Oils and greasy waste

• Cat litter, dog faeces, disposable nappies

• Coal, coke, ash

• Synthetic fabrics and plastics

These materials tend to attract rodents, introduce pathogens, and contaminate compost, creating more problems than benefits in a home composting setup.

Cold Composting

From everyday practice, cold composting is the most common method used by home gardeners, where materials are added gradually and decomposition happens slowly over several months with minimal effort.

Key characteristics:

• Advantages include being easy to manage, low maintenance, and suitable for small gardens

• Disadvantages include slower breakdown and it may not kill weed seeds or pathogens

This method suits growers who value simplicity over speed and are comfortable letting time handle the process.

Hot Composting

From practical experience, hot composting involves building a large, well-balanced pile all at once and managing moisture and aeration carefully so temperatures rise high enough to destroy weed seeds and pathogens.

Key points to consider:

• Advantages include faster compost production, safer handling, a wider range of materials, and higher nutrient retention

• Disadvantages include requires more attention and needs sufficient space

• Choosing the right system depends on available climate, types of waste you generate, and what you deal with most often

This method suits growers who want speed and control and are willing to stay actively involved in the process.

Composting in Different Climates

From hands-on work across regions, I’ve seen that composting genuinely works worldwide, but climate strongly affects its speed and management.

Warm and tropical conditions:
In warm, tropical climates, compost breaks down quickly, but piles may dry out, so regular moisture checks are important to keep the process active.

Cold and humid conditions:
In cold areas, decomposition slows, especially in winter, and insulating piles helps retain heat. In humid regions, proper airflow and enough browns prevent excess odours.

By adjusting to local conditions, I’ve consistently found better control, which improves results and prevents common problems before they disrupt the composting process.