Lemon thyme (Thymus serpyllum 'Pygmaeus')
Thymus serpyllum 'Pygmaeus', known as Lemon thyme, is a dense, low-growing perennial ground cover perfect for sunny, dry landscapes.
Complete Plant Information
Overview
Thymus serpyllum ‘Pygmaeus’, commonly recognized as Lemon thyme, is valued by gardeners for its extremely prostrate and dense growth habit, forming a tight, evergreen mat ideal for ground cover applications. This variety of creeping thyme spreads slowly via rooting stems, creating a rugged, textural carpet that thrives where other plants might struggle. It is celebrated for its low profile and tolerance for poor, rocky conditions, making it a highly resilient ornamental choice.
While its specific leaves are noted as aromatic, this cultivar is typically grown for its excellent landscape performance rather than culinary use, unlike its common culinary cousin. The plant produces attractive summer blooms, generally appearing in shades of purple-pink, adding seasonal color atop its dense foliage mat. Gardeners appreciate Thymus serpyllum ‘Pygmaeus’ for its low maintenance needs once established in a suitable full sun location.
It performs well in USDA Zones 4 through 8, offering dependable, spreading coverage that suppresses weeds and stabilizes sunny banks. The structure of the woody-based perennial ensures it retains visual interest even through mild winters, offering year-round structure in appropriate climates.
Fast Facts
- Plant Family: Lamiaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 4-8
- Size at Maturity:
- Height: 0.25 ft
- Spread: 1-1.5 ft
- Bloom Time: June to July
- Bloom Description: Purple-pink
- Sun Exposure: Full sun
- Water Needs: Dry to medium
- Maintenance Level: Low
How to Grow
Plant Lemon thyme in the best location during spring or fall, ensuring the spot receives consistent full sun exposure throughout the day. This creeping thyme cultivar thrives best when situated in loose, sandy, gritty, or rocky soils that offer sharp drainage. It particularly dislikes consistently moist or wet conditions, which significantly increase the risk of root rot developing in the dense mats of Thymus serpyllum ‘Pygmaeus’.
In terms of regular care, drought tolerance is a key feature; water only sparingly once the plant is established. Fertilization is usually unnecessary, as this species prefers nutrient-poor soils. To maintain a tidy appearance, especially as the stems develop woody bases, lightly shear or cut back the stems after flowering or as growth becomes sprawling.
For older plants that have become overly woody or sparse, division is the best method for rejuvenation or propagation. Since Thymus serpyllum ‘Pygmaeus’ is a cultivar, division or taking cuttings is strongly recommended over seed propagation to ensure you maintain the desirable ‘Pygmaeus’ characteristics. In colder zones, ensure the plant is well-established before deep winter sets in.
Landscape Uses
Thymus serpyllum ‘Pygmaeus’ excels as a versatile, fragrant ground cover, particularly suited for small areas where a very low-growing mat is desired. Its spreading nature makes it perfect for filling in crevices in rock gardens or sprawling gracefully over small stones and ledges. This creeping thyme is highly effective used as an edging material along sunny paths or patios, softening hard lines beautifully.
Consider using it as a low-maintenance lawn substitute in small, manageable areas that receive heavy foot traffic, provided the soil drainage is excellent. Its ability to tolerate dry, shallow, and rocky soil opens up many possibilities for use on banks or slopes where planting maintenance is difficult. It pairs well with sun-loving, slightly taller perennials that won’t shade out its need for full sun.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Thymus serpyllum, commonly called wild thyme, creeping thyme or mother-of-thyme, is a hairy, prostrate, creeping, woody-based perennial which is primarily grown as an ornamental ground cover. It is rarely used in cooking (Thymus vulgaris is the culinary thyme most commonly used in cooking). ‘Pygmaeus’ is a dense, slow-growing ground cover with purple-pink flowers and pubescent gray-green leaves.
Tolerances
- Deer
- Drought
- Dry Soil
- Shallow-Rocky Soil
- Air Pollution
Potential Problems
This plant generally experiences no serious challenges with pests or diseases under ideal cultural conditions. The primary threat to Thymus serpyllum ‘Pygmaeus’ is root rot, which almost always results from excessively moist or poorly-drained soils; ensure sharp drainage is prioritized during planting. In extremely hot and dry summer periods, gardeners should occasionally scout for minor infestations of spider mites.
Frequently Asked Questions
What hardiness zones is Lemon thyme suitable for?
Lemon thyme, or Thymus serpyllum ‘Pygmaeus’, is hardy and can thrive reliably in USDA Zones 4 through 8.
How large does Thymus serpyllum ‘Pygmaeus’ grow?
This variety is very low-growing, typically reaching only about 0.25 feet tall, but it will spread to cover an area between 1 and 1.5 feet wide over time.
What sun exposure does Lemon thyme need?
For the best performance, dense mat formation, and flowering, Thymus serpyllum ‘Pygmaeus’ requires placement in full sun.
When does Thymus serpyllum ‘Pygmaeus’ bloom?
This variety generally produces its attractive purple-pink flowers throughout the early summer months, specifically from June into July.
Conclusion
Thymus serpyllum ‘Pygmaeus’ offers exceptional value as a tough, low-maintenance perennial ground cover that stabilizes dry, sunny slopes and edges. The dense, spreading habit of Lemon thyme provides excellent texture and seasonal interest with minimal input from the gardener. Before planting, confirm that your chosen site provides the necessary full sun and excellent drainage to ensure this creeping thyme thrives for years to come.
Companion Planting
When selecting companions for Thymus serpyllum ‘Pygmaeus’, focus on other low-water, sun-loving Mediterranean herbs and rock garden favorites. Plants that share a preference for dry, sharp-draining soil will ensure none of your plantings suffer from competing watering needs. Consider pairing it with Sedum varieties, low-growing ornamental grasses, or sun-loving Dianthus which offer contrasting textures while matching the cultural requirements of this aromatic thyme.
Wildlife Benefits
The dense flowering stems rising just above the foliage mat of Thymus serpyllum ‘Pygmaeus’ are highly attractive to beneficial insects. The tiny, tubular flowers provide an excellent nectar source, drawing in essential pollinators like bees during the summer bloom period. Planting drifts of this creeping thyme encourages biodiversity in your sunny borders while you enjoy the benefits of its evergreen ground cover performance.
