Origanum vulgare (Common Oregano)
Origanum vulgare, also known as Oregano, Common Oregano or Wild Majoram, is a semi-evergreen, aromatic, low-growing herbaceous perennial with a woody base that has a spreading habit forming a small dense ground cover.
The leaves are small and green. The flowers are usually pink but can also be light purple or white, depending on the subspecies, and appear in clusters arranged in panicles during the summer.
This plant is native to Europe, North Africa, and most of Asia but is widely cultivated worldwide for its culinary and medicinal uses.
Oregano is often confused with Marjoram, but although they belong to the same genus, they have different characteristics.
HEIGHT & WIDTH
Common Oregano Scientific name
- Botanical name: Origanum vulgare (oh-RI-guh-num vul-GAR-ee)
- Family: Lamiaceae (lay-mee-AY-see-ee)
- Common name: Oregano, Common Oregano, Wild Marjoram
- Synonyms: Thymus 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.
|Derives from latin word “vulgaris,” which means common or ordinary.
How to identify Origanum vulgare
Origanum vulgare is a small herbaceous perennial that 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.
Forming a spreading habit due to its rhizomatous underground stems that send shoots along their length.
It has dense foliage of green leaves and erect flower stems bearing clusters of tiny pink flowers with purple bracts.
The foliage has an average height of 5 to 10 cm (0.2 to 0.3 ft) and 50 cm (1.6 ft) when in flower. The width is around 40 – 50 cm (1.3 – 1.6 ft)
The stems are upright or spreading, reddish-green, hairy, and woody at the base.
They are squared, with opposite leaves at each node
Clusters of tiny pink flowers are arranged in panicles with multiple branched stems growing from a central stem.
The leaves are small and hairy. The colour is green on the upper side and greyish-green on the underside.
They are entire, in some cases, minutely toothed, oval to elliptical and acute tip. The petiole is short and hairy.
Covered with numerous essential oil glands that release volatile oils with a pleasant fragrance. The fragrance is more intense when the leaves are rubbed or crushed.
The leaf is, on average, 15 to 42 mm (0.6 to 1.6 in) long and 8 to 22 mm (0.3 to 0.8 in) wide.
The flowers are grouped in rounded clusters that are arranged in a loose panicle along the stem. The panicle’s height ranges from 6 to 18 cm (2.3 to 7 inches) and its width is 4 to 7 cm (1.5 to 2.7 inches).
The flowers are pink, light purple or white, depending on the subspecies. They are two-lipped, the upper lip has 2 lobes, and the lower lip has 3 lobes.
The corolla is 4.5 to 10mm (0.1 to 0.4 in) and is inserted inside a bell-shaped calyx composed of 5 maroon-coloured triangular sepals.
The flowers bloom during the Summer.
Origanum vulgare Habitat
Origanum vulgare as the name suggests (origanum = “joy of the mountain”), is a mountain plant, that can be found at altitudes up to 2000m (6500 ft).
It is well adapted to grow in rocky and mountainous regions. It can be found in various types of habitats, including rocky slopes, forest edges and mountain meadows.
It thrives in dry conditions and can tolerate full sun exposure.
Origanum vulgare subspecies
Due to its wide distribution and some slight differences in its appearance, there are several recognized subspecies:
|O. vulgare subsp. Vulgare
|Europe to most of Asia
|Purple bracts, pink flowers
|O. vulgare subsp. Glandulosum
|Algeria and Tunisia
|Green Bracts, white flowers
|O. vulgare subsp. Gracile
|Turkey to Central Asia
|Green or purplish bracts, white or pink flowers
|O. vulgare subsp. Hirtum
|SE. Europe and Turkey
|Green bracts, white flowers;
|O. vulgare subsp. Virens
|Portugal, Spain and Morocco
|Yellowish-green bracts, white flowers;
|O. vulgare subsp. Viridulum
|S. Europe to Himalaya
|Green bracts, white flowers;
* standard culinary oregano
Origanum vulgare Usage
Common Oregano is appreciated as an ornamental plant due to its dense mat-forming habit and pretty panicles of tiny pink flowers.
It can be used in the following ways:
- Rock Gardens: It is well-suited for rock gardens. Its ability to thrive in rocky and stony areas and its compact mat form makes it a natural fit for rock gardens or other alpine-style planting areas.
- Garden Borders and Edging: The compact spreading growth of Common Oregano makes a neat border for flower beds and pathways.
- Ground Cover: It can be used as a ground cover to make a smooth transition from pathways to other plantings, or intermingled with other plants.
- In containers: It can easily be grown in containers, making it a versatile choice for patio gardens, balconies, or other limited-space areas. Check the guide to growing Oregano in pots.
Oregano is a very popular herb, known for its slightly spicy and strong taste. People use it in various dishes like meat, fish , pizzas, salads, soups etc. Typically, it is sprinkled towards the end of cooking to preserve its strong flavour.
It is also used to flavour olive oil and vinegar.
Its leaves can be used fresh or dried. The flowers are also edible.
Of all the subspecies of Origanum vulgare only the following are suitable for cooking: O. vulgare subsp. hirtum (Greek oregano), O. vulgare subsp. gracile (Russian oregano)and O. vulgare subsp. glandulosum (Algerian oregano).
Origanum vulgare was used in folk medicine to treat digestive and respiratory illnesses, such as indigestion, colds, sore throats, cough, bronchitis, etc.
Research has demonstrated its antioxidant and antimicrobial activities.
Due to its antiseptic and antioxidant properties, the essential oil of oregano is used in the production of soaps, shampoos and skin creams.
Oregano contains compounds that repel insects, so it will act as a natural pest repellent if you plant it in your vegetable garden. Additionally, its intense aroma may mask the scent of the vegetables, making it harder for pests to locate them.
Specifically, it is known to repel pests like aphids, cabbage moths, cucumber beetles, and certain types of mites.
Common 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.
Common Oregano flowers can be used in potpourris, Tussie-mussies and bridal bouquets as a symbol of joy and happiness.
How to care for Origanum vulgare
This plant is frost-hardy and can tolerate temperatures down to -15ºC (5ºF), 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. However, due to its spreading habit that touches the ground, organic mulches may retain too much moisture and can cause the stems to rot, so it is best to use gravel mulch.
Origanum vulgare prefers full sun. It thrives in bright, direct sunlight. Providing it with at least 6 hours of direct sunlight per day is ideal for its growth and overall health.
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.
It prefers well-drained stony, or sandy soils, but it can also do well in chalky soils. Don’t plant it in wet areas. It doesn’t like soggy soil, which can cause root rot and fungal diseases.
It thrives best in soils that are slightly alkaline to neutral in pH, but can also tolerate slightly acidic soils.
Common Oregano is moderately drought tolerant and can go for some without water once it is established (about 3 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 give it some water. Just make sure to let the soil completely dry out before watering it again.
During the first year after planting, it’s essential to water the young oregano every two to three weeks, especially in the summer (or more often if the soil is sandy). 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 the oregano establish strong roots that can access deeper soil and better withstand dry conditions in the future.
When you water the plant, make sure to 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 as well. With deep roots, the plant can withstand longer dry periods since the lower soil layers stay moist for a longer time.
To preserve the soil´s moisture, you should add mulch around the plant’s root area. Gravel is the best option for mulching.
Pruning Oregano helps maintain its shape and encourages bushier growth.
- Give it a cleaning prune in early spring. You should cut back the old, weak or overly crowded stems. This will allow for better air circulation and light penetration which will promote healthy growth. Prune it down completely 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 early to mid-summer to help maintain its shape and encourage new growth.
- Give it a light prune regularly from late spring to the end of summer to prevent the plant from becoming too leggy and to harvest its leaves for cooking.
When to plant Origanum vulgare
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 vulgare
Common Oregano is best propagated by stem cuttings or layering. Propagation by seed may lack the desired fragrance or flavour due to unpredictable genetic variation. So if you have a plant that has the wanted qualities, it is better to clone it, either by cuttings or layering.
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
Article from Jardin Sec
Vol XII from FloraIberica