Can sugar control weeds in the garden?
A natural approach to weed control might already be in your pantry.
Pandemic lockdowns have had few silver linings but perhaps spending more time in the garden is one of them. Weeds are every gardener’s nemesis but new research from the CSIRO suggests sugar can reduce the germination rates of some weeds, namely herbaceous annuals with soft green stems, fleshy green leaves and exotic (non-native) grasses. The South-Western Sydney local government area of Liverpool tested it out and found sprinkling a thin layer of sugar on their native garden before mulching (half a kilogram per square metre) was very effective. After six months no weeds were germinating. It works because the sugar supports the growth of microbes in the soil that metabolise the available nitrogen. The native plants in both Australia and New Zealand are adapted to a low nitrogen environment while the weeds flounder. But don’t try this in your vegetable patch as these plants need the nitrogen. And not near paved areas either or you’ll have a new problem of ants! Using sugar for weed control is best when you’re establishing a new native garden. At a time when low chemical and more organic gardening methods are desirable, sugar provides a natural solution.