The sweet and unusual aroma of marjoram makes it a favourite in the herb garden, and the dried leaves give a marvellous flavour to a variety of dishes.
Marjoram is one of the most fragrant plants in the herb garden. Legend says that the plant was created by the goddess Venus, and the sweet scent and flavour came from her touch. The name marjoram is given to a group of plants which belong to the Labiatae family. All marjoram are of the genus Origanum. Those most commonly grown in gardens include oregano or wild marjoram (O. vulgare), pot marjoram (O. onites) and sweet or knotted marjoram (O. majorana).
Oregano or wild marjoram is the favourite herb in Italian kitchens. The plant is native to Europe, and it thrives on chalky soils in particular. A bushy perennial plant, it grows to about 75 cm (2-1/2’) high. Oregano has small pale rosy- purple flowers in summer and grey-green leaves which it loses in winter. There is also a yellow-leaved form, ‘Aureum’. The leaves of oregano are particularly pungent in flavour and aroma; only a small quantity need be added to the various savoury dishes in which this herb can be used.
Pot marjoram is also a hardy perennial, but much smaller than oregano. It grows to a height of only 25 cm (6”), and it tends to lie along the ground with the shoots producing roots at the leaf joints. Outdoors, the plant can cover a space at least 30 cm (1’)square, but it is an ideal herb for growing indoors in a large pot. Pot marjoram produces lovely purple flowers on 45 cm (1-1/2’) tall stems in late summer.
Much more delicate than either of these types is sweet or knotted marjoram, which must be treated as a half-hardy annual in the more temperate climate. The flavour is much milder and more pleasant than the strong one of oregano, and is particularly good for enhancing meat dishes. Sweet marjoram grows to about 20 cm (8”) high, with round grey leaves and clusters of minute white or pink flowers which grow from greyish green pea-like buds in the leaf joints. The whole plant has a greyish tinge and is softly hairy.
All the marjorams prefer a light, well drainedin a site which gets full sun for most of the day. If the site is on the clay soil, work in coarse sand or otherwise improve the drainage before sowing. Marjoram dislikes an over-acid soil, so apply hydrated lime if the soil is very acid.
Grow pot marjoram or wild marjoram in the same way, from seed sown outdoors in early or mid-spring. Take out drills 2 cm (3/4”) deep and 20 cm (8”) apart, and sow the seed thinly. Germination should take place in two to three weeks. When the first three true leaves have formed, put the young plants into permanent positions, spaced about 30 cm (1’) apart.
Cultivation requirements are minimal for marjoram. Young plants must be kept well weeded and well watered, especially in dry weather. Older plants, however, are not so sensitive to drying out, although they will need watering in a drought.
From a spring sowing, marjoram leaves will be ready for harvesting just before the plants flower in mid- to late summer. Pick the leaves in the morning of a dry day, and put them to dry in a very dry, dark place, which is warm but not too warm. When thoroughly dry, store the leaves either whole or crumbled, in an opaque, airtight container. There may be a second, smaller crop of leaves before the winter.
Wild marjoram will lose all of its leaves in autumn, but the roots should survive a winter outdoors, to produce fresh shoots the following spring. Protect the plants with mulches or by covering with cloches if the winter is unusually cold.
Pot marjoram can be lifted in early autumn after the best leaves have been picked and potted up for winter use. Cut back the plants by about two-thirds before they begin to die down and, when new shoots begin to appear, pot them into a standard potting. Keep the plants indoors during the winter in a warm, light position; you should have sufficient growth to provide fresh leaves as needed. Return them to the soil the following spring. You can, of course, keep the plant in its pot permantly (renewing the compost from time to time) and simply plunge the pot in a border for the summer, thus avoiding constant repotting and root disturbance. The plants may survive longer by this method, as they dislike repotting.
Cultivation for sweet marjoram is different from that of the other species, mainly because the plant is less hardy. Sow sweet marjoram in a seed tray in mid-spring, using a good quality seed compost. You must be able to maintain a temperature of 15°C (60°F), so keep the seed tray in a propagator, frame or green-house until germination, which should take about one to two weeks. Prick out theto a spacing of 5 cm (2”) apart. They should be ready for by early summer: space them about 15 cm (6”) apart.
Sweet marjoram tends to be slow growing, and the plants should be shaded from strong sunlight until they are established. Hoe frequently to aerate the soil and remove any, but take care not to damage the plants with your hoe. Water well in dry weather. The leaves will be ready for cutting from mid-summer, just before the plant flowers. Dry and store them like the other marjorams. As sweet marjoram will not survive cold weather and does not do well in a pot, dig up the remains of the plants in autumn.