Origanum laevigatum (Smooth Oregano)
Origanum laevigatum, is often referred to as Smooth Oregano or Ornamental Oregano. It’s a fragrant, semi-evergreen herbaceous perennial with small dark green leaves that create a dense and low-growing ground cover. Rising above the foliage are tall, slender spikes of purplish-pink flowers adorned with maroon bracts.
Native to the Eastern Mediterranean Region, specifically Turkey, Syria, and Cyprus. This plant is cultivated worldwide for its admired ornamental value.
HEIGHT & WIDTH
Smooth Oregano Scientific name
- Botanical name: Origanum laevigatum (oh-RI-guh-num lee-vih-GAY-tum)
- Family: Lamiaceae (lay-mee-AY-see-ee)
- Common name: Smooth Oregano, Ornamental Oregano
|Origanum||There are two versions for the origin of the name;|
1- Derives from a combination of two Greek words “oros” meaning mountain and “ganos” meaning joy. So Origanum means “Joy of the mountain”.
2- Derives from the Greek word “origano” meaning bitter, referring to the bitter flavour of these herbs.
|laevigatum||Derives from the Latin word “laevigatus”, which means “smooth” or “polished”. Relative to the smooth or polished leaves of the plant.|
How to identify Origanum laevigatum
Origanum laevigatum is a compact low-growing herbaceous perennial that can be considered a subshrub because it develops a woody base as it matures.
It is evergreen in milder climates but may lose its foliage during the winter in very cold climates where it dies back each year in autumn and then comes back with fresh growth in spring.
Smooth Oregano spreads laterally from year to year, due to its horizontal underground stems ( rhizome) that send shoots and roots along their length, eventually forming a very dense ground cover.
It has dense foliage of dark green leaves, forming a creeping mat. Emerging from the foliage, slender stems rise gracefully, adorned with clusters of tiny purple-pink flowers in panicles, giving the plant a soft and hazy appearance.
The foliage has an average height of 10 cm (0.3 ft) and 50cm (1.6 ft) when in flower.The width is 40 to 50 cm (1.3 to 1.6 ft) or more.
The stems are upright or ascending, green to reddish-green, and woody at the base. The underground stems (rhizome) form new roots and shoots at the nodes.
They are squared, with opposite green leaves at each node
Clusters of tiny purple-pink flowers with maroon or purple bracts are arranged in a panicle.
Once the flowers have dried, the bracts and stems remain intact, creating a stunning wire sculpture that adds interest during autumn and winter.
The leaves are small and aromatic. They are hairless which gives a very smooth appearance hence the common name “Smooth Oregano”.
They are entire, lance-shaped to oval, with an acute tip and a very short stalk.
The leaf changes colour during the seasons In the winter it is green, and in the summer it changes to bluish-green and deepens in colour as the summer progresses.
The leaf is, on average, 1 to 2 cm (0.4 to 0.8 in) long.
The inflorescence is composed of clusters of tiny flowers arranged in a loose panicle along the stem.
The flowers are small (around 15 mm/0.6 in length) and purplish-pink, with two lips. The upper lip is notched, and the lower lip has 3 lobes.
The tubular corolla is surrounded by vividly coloured bracts with deep-purple or maroon tones.
Bloom time is usually during summer but may extend from late spring to early autumn.
Origanum laevigatum Habitat
Smooth Oregano is native to the Eastern Mediterranean region, including countries like Turkey, Syria, and Cyprus.
It is well adapted to grow in rocky and dry regions. It can be found in various types of habitats, including rocky slopes, forest edges and mountain meadows usually on limestone.
It prefers sunny places but can also be found in partial shade.
Origanum laevigatum Usage
Smooth Oregano is a wonderful plant for your garden. A sculptural presence with its long wirey flower stems swaying with the breeze. Additionally, it forms a dense year-round ground cover in milder climates.
It can be used in the landscape in the following ways:
- Ground Cover: Its low-growing, dense mat of dark green leaves makes it an excellent ground cover, adding texture and visual interest to landscapes.
- Borders and Edges: Planted along garden borders or pathways, Smooth Oregano creates a neat and attractive border, defining the edges of garden beds. It can also be planted at the foot of deciduous trees because it supports root competition.
- Rock Gardens: Its ability to thrive in rocky and dry conditions makes it a popular choice for rock gardens. Its compact growth and bending stems splayed over the rocks add beauty to rocky landscapes.
- Container Planting: Smooth Oregano does well in containers, making it suitable for patios, balconies, and window boxes. Its aromatic leaves also add a delightful scent. (for tips on growing in containers check Origanum in pots)
- Cottage Gardens: Its charming appearance and fragrant leaves make it a natural fit for the informal and whimsical style of cottage gardens.
- Xeriscapes: With its drought tolerance, Smooth Oregano suits water-wise landscapes like xeriscapes, whose ornamental qualities contribute to the overall aesthetic.
- Wildlife garden. The small flowers of this ornamental oregano attract pollinators like bees and butterflies, making it a valuable addition to gardens focused on supporting local wildlife.
Smooth Oregano flowers are rich in nectar attracting pollinators such as bees and butterflies. Like other oregano varieties, this plant is a valuable addition to the biodiversity of your garden and is ideal for wildlife gardens.
The aromatic leaves of this ornamental oregano can be used in crafting, such as making potpourri, bouquets, or scented sachets.
How to care for Origanum laevigatum
This plant is quite hardy tolerating temperatures down to -12ºC (10ºF), as long as the soil is well drained. Cold and humid soil can be fatal to it.
Add a thick layer of mulch to shelter the roots from low temperatures.
Smooth Oregano prefers full sun, but it can also do well in partial shade.
In places with very hot climates or strong sunlight, it can be helpful to protect plants from the afternoon sun to prevent leaf damage. Providing partial shade during the hottest hours of the day can protect the plant from excessive heat and intense sunlight.
Smooth Oregano prefers well-drained stony, or sandy soils. Avoid planting it in wet areas, as it dislikes soggy soil, which may lead to root rot and fungal diseases.
It prefers alkaline soils but can tolerate mildly acidic soils however you should avoid highly acidic soils.
Smooth Oregano is drought tolerant and can go for some months without water once it is established (about 4 months of drought if the temperature is not too hot).
Once established, it usually does not need watering. However, if there’s a long period without rain or very hot weather, you should water it, making sure to let the soil completely dry out before watering again.
During its first year after planting, it’s essential to water the young plant every two to three weeks or more often if the soil is sandy and the weather is very hot. This is because the plant is developing its roots, which are still short and can only reach the shallow parts of the soil that dry out faster. By providing regular watering, you help it establish strong roots that can access deeper soil and better withstand dry conditions in the future.
When you water the plant, give it plenty of water, allowing the soil to get a good soak. This way, the water can sink deep into the soil, helping the roots grow deeper. With deep roots, the plant can withstand longer dry periods since the lower soil layers stay moist for longer.
To preserve the soil´s moisture, you should add mulch around the root area of the plant. Gravel is the best option for mulching so that the stems touching the ground will not rot during the wet winter months.
Pruning Smooth oregano helps maintain its shape and encourages bushier growth.
- Give it a cleaning prune in early spring. You should cut back the stems that are old, weak or overly crowded. This will allow for better air circulation and light penetration, promoting healthy growth. Prune it down entirely if it is overgrown or weak. This will enable new stems to grow from the base.
- Give it a hard prune (always cutting above a healthy set of leaves) immediately after the flowering period typically late summer to help maintain its shape and encourage new growth. However, if you like to see the wiry sculptural structure during the winter, wait until early spring to give it the hard rejuvenating prune.
When to plant Origanum laevigatum
The best season to plant is in spring or autumn, depending on your climate. Avoid planting during periods of extreme temperatures.
If you live in a location with moderate weather, you should preferably plant during autumn. By doing so, the plant gets a chance to develop its roots during the cooler months before the arrival of summer’s hot temperatures. However, if you encounter severe winters, it’s better to wait until spring when the danger of frost has passed and the soil has warmed up, creating a more favourable environment for the plant to thrive.
How to propagate Origanum laevigatum
Smooth oregano is best propagated by stem cuttings or layering. But propagation from seed is also an option.
Stem cuttings: take softwood cuttings in spring before it starts blooming or semi-hardwood cuttings in late summer or early autumn.
- Cut the stem just below a leaf node.
- Remove the lower leaves, leaving a few pairs of upper leaves intact.
- Plant in a well-draining medium. Keep the medium consistently moist and provide indirect light.
- Once the roots have developed, transplant the rooted cuttings into individual containers and grow in cold frame during the first winter.
Layering: in autumn or spring
- Choose a mature plant.
- Take a flexible young branch and bend it down to the ground
- Dig a shallow hole, place the middle of the branch in it, and cover with soil.
- Place a peg or a rock on top to hold it down.
- After rooting, cut the stem from the mother plant.
- Replant the rooted stem into prepared holes or pots filled with well-draining soil.
- Water thoroughly and keep them adequately moist while they establish.
Seeds: sow seeds in autumn.
- Sow the seeds in a well-draining medium. Lightly press the seeds into the surface of the soil without covering them.
- Maintain consistent moisture and provide indirect light.
- Germination typically takes 2-4 weeks. Once the seedlings have grown a few sets of true leaves, transplant them into individual containers and grow in cold frame during the first winter.
A good online source for plant propagation techniques can be found in RHS propagation article.
If you prefer books, I can recommend the following:
Sources of information used for this article
I researched this plant in the following book, which I highly recommend to anyone interested in dry gardening.
Article from American Rock Garden Society