With dry conditions and water restrictions in many areas of Australia, gardeners are turning to mulch to help prevent excessive moisture loss and keep the soil cool. However, Don suggested that as we enter the drought, conventional mulching might not be such a good idea.
Water repellent soils
When soils dry out they can become water repellent, or hydrophobic. When this happens, water just runs off instead of soaking into the soil.
The prime cause of hydrophobia is decomposing matter, and mulches that break down quickly (for example pea straw and sugar cane mulch) contribute to the problem of water repellence. Mulches made from plants with a high oil content (such as gum trees, paperbarks and tea trees) also cause hydrophobia because as the oils break down they wrap themselves around the soil particles. Sandy soils are most affected as their particles are much larger than clay particles, thus providing more area for the oils to