Common thyme

Botanical data

Family

Lamiaceae (Lamiaceae)

Height

0.1–0.3 m

Width

0.2–0.4 m

Habit

Creeping

Growth rate

Slow

Position

Full sun

Soil

Sandy, Chalky

pH reaction

pH 6–8

Moisture

Dry

Bloom

May–July

Hardiness

USDA 5a–9b

Propagation

From cuttings, By division

Characteristics

A low, spreading or cushion-forming sub-shrub with tiny, narrow, strongly aromatic leaves and numerous small pink-violet flowers clustered at the shoot tips. It reaches 10-30 cm in height and 20-40 cm in width, forming a dense, dome-shaped clump whose base turns woody with age; the lower shoots lie sideways but - unlike creeping thyme (Thymus serpyllum) - do not root at the nodes. The stems are four-angled, the young ones finely hairy. The leaves are opposite, 4-8 mm long, linear to lance-shaped, with distinctly rolled-under margins - grey-green above and white-felted beneath, which gives the whole plant a silvery cast. The aroma comes from oil glands in the leaf skin (mainly thymol and carvacrol); in hot weather it hangs over the clump, and it is released most strongly when a leaf blade is rubbed between the fingers. The two-lipped flowers, about 5 mm long, are gathered in false whorls that form dense heads at the shoot tips; flowering runs from May to July, and the colour ranges from white through pink to lilac-violet. Annual growth is modest, but the plant reaches its final habit as early as the second or third year. It is evergreen, though after harsh, windy winters some of the leaves turn brown and drop, and the plant regrows in spring from the lower parts of the shoots. It needs full sun and a well-drained, lean and distinctly dry soil with a pH of 6-8, ideally neutral to alkaline; it does not tolerate standing water at all. It is sometimes confused with creeping thyme (Thymus serpyllum), from which it differs in its taller, bushier habit with a woody base and a stronger, more concentrated aroma.

Popular cultivars

‘Silver Posie’

A cultivar with grey-green leaves edged in creamy white and pale pink flowers, growing to about 20-30 cm. Planted mainly for ornament - for edging, rock gardens and containers.

‘Erectus’

A form with an upright, bushy habit and narrow, grey-green leaves, reaching about 25-30 cm. Easier to harvest than the cushion-forming types and popular for low edging in herb gardens.

‘Deutscher Winter’

A culinary cultivar widespread in Central Europe, with broader leaves and a strong, spicy aroma, chosen above all for its good hardiness and for harvesting throughout the season.

Growing and care

Companion plants

The evidence level indicates whether the relationship is backed by research, observation, or gardening tradition.

Toxicity

History and origin

Thyme was already prized in antiquity - the Egyptians used it for embalming, the Greeks as a symbol of courage, and the Romans spread it as a culinary herb throughout Europe. References to Egyptian embalming, however, concern aromatic herbs of the genus Thymus in general rather than Thymus vulgaris itself: this species grows wild in the western part of the Mediterranean basin - on the limestone, stony slopes of Spain, southern France and Italy, where it is one of the characteristic components of the low garrigue scrub. It reached Central Europe with monastic cultivation: medieval herb gardens spread it north of the Alps as a culinary and medicinal plant. It was scientifically described by Linnaeus in Species Plantarum (1753). The oil has been distilled from the herb since at least the 16th century, and in the 18th century thymol was isolated from it - used as an antiseptic for washes and dressings even before the age of antibiotics. Thyme herb (Thymi herba) remains a pharmacopoeial raw material, used in expectorant syrups and lozenges. It is grown for its oil today in Spain, France and Morocco, among other countries, while in the kitchen the species has established itself as a permanent ingredient of bouquet garni and the herbes de Provence blend.

Uses

For herb and rock gardens, dry walls and crevices, as low ground cover, and in pots. The leaves are used as a culinary herb and for infusions. It is planted in May, 25-35 cm apart - after two or three seasons the clumps knit together into a low, aromatic carpet. The best positions are sun-warmed banks, the southern edges of beds, the tops of dry walls, crevices between paving slabs and gravel beds; it is worth mixing the substrate with sand or grit and mulching with grit rather than bark - bark holds moisture at the root collar and encourages rot. Its natural partners are lavender and rosemary along with other plants of dry sites; it should not be combined with perennials that need constantly moist soil, nor fed with nitrogen, because lush growth comes at the expense of aroma. In containers a drainage hole and a free-draining substrate are essential. In the kitchen the sprigs are added at the start of cooking - the aroma is released slowly and is not lost during long cooking, which is why thyme suits braised meats, pulses, roasted vegetables and marinades, and dried in the shade it keeps its flavour for months. Flowering clumps are worked intensively by bees, so part of the clump is left untrimmed so that it can bloom - the rest is cut just before flowering, when the oil concentration is highest.

Trivia

• Thymol, thyme's essential oil, has strong antibacterial properties and is an ingredient in many mouthwashes.
• Thyme honey, especially the Greek variety, is highly prized for its intense aroma.
• In southern France the same species occurs in several chemical varieties (chemotypes) that differ in the main component of the oil - thymol, carvacrol, linalool or geraniol. Plants from neighbouring sites can therefore smell distinctly different despite looking identical.
• Thymol, the very oil component responsible for thyme's scent, is the active substance in preparations used in beekeeping against varroosis - infestation by the parasitic mite Varroa destructor.

Frequently asked questions