Know your leaves. Oak, beech leaves and pine needles are more acidic than others. Add no more than 10 per cent of acidic leaves to your composter or compost these materials separately. Use finished compost on acid-loving plants like tomatoes, strawberries and rhododendrons. If you do not wish to add them to your composter, use them as mulch for acid-loving plants.
Some leaves take longer to break down than others.
Oak leaves are one example. Others include such waxy leaves as laurel, rose, pine needles, holly and rhododendron. Shredding these leaves or mixing them with more nitrogen-rich materials will help to speed up the decomposition process. Walnut and butternut leaves should be composted separately. They contain a substance which is toxic to many plants, called juglone.