The very best protection for plants against drought is a humus-rich, moisture-retentive soil. Preparing a soil before planting with generous additions of a nutritious compost, home-made or purchased, and/or well-composted manures helps to create a spongy soil that fosters a lively community of beneficial micro-organisms, which in turn act to support plant health. Mulching is a useful secondary protective measure. As air and soil temperatures warm significantly, usually in late spring or early summer, give a target area a long, slow, deep watering, preferably in the early morning, then mulch around the plants with more good quality compost or topsoil.