Gardener with basket of egg shells spreading crushed shells around tomato plant - VH-studio/Shutterstock A quality eggshell contains about 2.2 grams of calcium carbonate, the compound that gives them ...

Renowned gardener Simon Akeroyd, author of 30 gardening books and former Garden Manager for the RHS (Royal Horticultural Society), advises against discarding egg shells after use. Instead, he suggests ...