These two culinary herbs are very closely related, with flavours that are almost indistinguishable. They represent two of about 20 species of Oregano, all members of the mint family, Lamiaceae. Origanum vulgare is often referred to as “wild oregano,” and indeed, it does grow wild in many areas around the Mediterranean, and as far east as Khirgizstan. There are several further subspecies of wild oregano, including Italian/Greek, Turkish, and Lebanese, each with their own subtle difference in flavour and character. Syrian oregano (O. syriaca) is also known as Za-atar, and is a characterful herb of the Middle East. A number of cultivars have also been bred, with variegated leaves, dwarf growing habit, golden foliage, stronger flavours, and so on.
The herb most often associated with Greek and Italian cuisine is Origanum vulgare hirtum, or Greek Oregano. This plant grows as a perennial and forms a small shrub from 20-80cm (8-32”) tall, with slightly hairy, rounded leaves, and spikes of flowers in purple or pink that bees adore. Curiously, oregano is high in antioxidants, and has been used as an antimicrobial and antiseptic agent. It is also said to be a rather strong sedative. The ancient Greek physician Hippocrates knew of oregano’s medicinal qualities and used the herb to treat wounds, as well as stomach and respiratory problems.
Marjoram (sometimes called Sweet Marjoram) is also a perennial, but is a little more sensitive to cold than oregano. In many countries, the two plants are considered synonymous, but marjoram has very slightly more citrus, pine, and camphor elements to its aroma and flavour. It grows in a prostrate habit, trailing along the ground, with smaller leaves than oregano, and tiny, knot-like nodes along its stems. For this reason, it is sometimes referred to as “knotted marjoram.” The plant known as French marjoram is actually a cross between marjoram and oregano, and is a common ingredient in herbes de provence. Rather than being sweet to the tongue, marjoram may have earned the sweetness of its name from being a symbol of happiness in ancient Greece.
How to Grow Marjoram and Oregano:
Difficulty: Easy. Both types are suitable for containers.
Timing: Sow indoors from mid-February to mid-April, and transplant out after April 15th. Marjoram can be direct sown in April, but wait until mid-May to direct sow oregano.
Sowing: Barely cover the tiny seeds, or sprinkle them on the surface of your starting mix, and keep moist.
Soil: Choose a site in full sun with light, well-drained soil and a pH of 7.0-7.5.
Growing: Both types benefit from being cut back. Oregano should be divided and transplanted every three years, once its stems become woody.
Harvest: If you want intend to dry either type, cut full stems before the plants bloom in early summer for the best flavour. Hang the stems upside-down in paper bags in a dark, airy room. Once the leaves are fully dry, they can be crumbled from the stems.
Storage: Store in sealed containers in a dark cupboard away from light. Both types can be frozen, but they retain their flavour very well when dried.
Seed info: Seeds are very slow to germinate, but remain viable for up to five years. Propagation by cuttings may be preferred by impatient gardeners.
Growing for seed: Isolate individual cultivars by 1km (½ mile) if growing for seed, as they are insect pollinated.
Pests & Disease: Pests are rarely an issue if plants are grown well. Watch for woodlice and slug damage on seedlings sown directly outdoors. Even then, the leaves are so aromatic and rough that plants may self-sow readily with no visible damage.