Cover up

Dry wood chips and bark aren’t the only way you can go about mulching. If you’re feeling bold, it might be worth trying a green mulch. There is a few different way you can do this:

  • Cover crops are crops that add nutrients to the soil between crops. Legumes are most commonly used as they fix nitrogen in the soil and make it available to the rhizobia in your plant roots. These crops have proven to be particularly useful around crops such as grapes. Easy plants are lucerne (Medicago truncatula is quite hardy) and clover (Trifolium repens grows among my flowers).


  • Green mulch can be a cover crop, but encompasses any crop that covers the grown and when cut back or mown can be left to break down in to the soil. Large scale this would encompass grass growing between rows of an orchard that is slashed and left to break down. In my garden I use nasturtiums (Nasus tortus) and borage (Borago officinalis).


  • Edible cover crops are exactly that – they double as mulch and food. In sunny north Queensland my brother and sister-in-law grow sweet potatoes throughout their garden bed. Self seeding leafy greens I find easiest in Perth so parsley (Petroselinum crispum), rocket (Eruca sativa), mustard (Sinapsis alba).


There are a few reasons you might plant a cover crop. Shading the soil will protect it from both harsh sun and dry wind. Ultimately keeping your soil moist keeps your soil alive. Fixing extra nutrients in the soil while living, or breaking down once cut will feed your perennial crops especially. Planting a variety will provide haven for a variety of beneficial insects and so save resources on pesticides. A dense cover crop will also suppress weeds.

I use babies tears (Soleirolia soleirolii) and native violets (Viola hederacea) in my shady areas as a green mulch to protect the soil and keep it from blowing or washing away. Oregano (Origanum vulgare) and trailing lotus (Lotus berthelotii) help my front yard, and paper daisies (Xerochrysum bracteatum) spread through wintertime down the side.