A crop planted primarily to protect and improve soil rather than for harvest. Cover crops prevent erosion, suppress weeds, add organic matter, and some (legumes) fix atmospheric nitrogen.
Cover crops are an essential sustainable gardening technique that improves soil structure and fertility without relying solely on fertiliser. In Australian gardens, popular cover crops include legumes like clover and vetch, which fix atmospheric nitrogen into the soil, and grasses like rye that prevent erosion and suppress weeds. Timing varies by climate zone and season: in cooler southern regions (zones 7-9), sow cover crops in autumn (March-May) for winter growth, then dig them in during spring (September-November). In warmer zones (1-6), plant during cooler months to maximise growth before summer heat.
The practice significantly reduces the need for added nitrogen fertiliser, saving money and benefiting the environment. Before planting your main vegetables or flowers, turn the cover crop into the soil 2-3 weeks before planting to allow decomposition. You'll find cover crop seeds at Bunnings and specialist suppliers. Common varieties include Hungarian vetch, buckwheat (excellent for warm climates), and subterranean clover. In vegetable beds, incorporate cover crops between crop rotations to maintain soil health. This technique works particularly well in raised beds and larger garden areas where space allows.