Common thyme (Thymus vulgaris) is a low evergreen sub-shrub and one of the most drought-tolerant herbs; wet soil harms it far more than a long dry spell. It needs full sun and poor, stony or sandy, free-draining soil, preferably limy (pH 6.5–8.0). Too much fertiliser makes growth soft and reduces the aromatic oils. Plant young plants from April, 25–30 cm apart, or divide older clumps in spring; seed germinates slowly and is best started indoors. Once established, water only during prolonged drought, and in pots make sure excess water drains away. Trim lightly in early spring and again after flowering, cutting back the soft growth but not into bare wood, to keep plants bushy – unpruned thyme becomes woody and falls open in the middle. It is hardy, but on heavy soil it can rot in wet winters, and a gravel mulch around the base helps. Harvest sprigs as needed; for drying, cut just before flowering when the flavour is strongest. Replace plants every four to five years.