Leisure and Cultural Services Department Planting Herbs in School Scheme 2017/18 Peppermint Sweet Marjoram Lemon Balm Mentha ××× piperita Origanum majorana Melissa officinalis Peppermint Scientific Name: Mentha × piperita Common Name: Peppermint Family: Lamiaceae (Labiatae) Genus: Mentha Place of Origin: Unknown Distribution: Widely cultivated all over the world, including Europe, North Africa and the United States. Mentha × piperita Characteristics • A perennial herb • Peppermint stops growing in winter. • It is tolerant of low temperatures and is suitable for year-round planting in Hong Kong. Mentha × piperita Growth Habits and Care • Peppermint thrives in a sunny environment, preferably with sunlight that is not too intense. • It should be placed in a cool, shady and well-ventilated spot on sizzling summer days. • It grows best in well-drained soil with organic matter. • Adequate soil moisture is essential for its proper growth. • Water moderately and avoid waterlogging to prevent infestation and infection. Mentha × piperita Propagation • By division • By rhizome cuttings Mentha × piperita Prevention and Treatment of Pests and Diseases • The stem of Peppermint is susceptible to rust in an environment with low temperatures, excessive moisture and poor ventilation. • Watch out for attacks from aphids, snails, slugs and fungi. • The plant should be pruned in a timely manner to ensure good ventilation. • Keep the environment clean and well-ventilated. • If pests or diseases are found, remove the infected parts and apply appropriate insecticide or fungicide immediately. Mentha × piperita Horticultural Application and Economic Value Peppermint has wide applications: • Horticulture – most suitable for cultivation in gardens or on rooftops • Medicinal use • Culinary use – cooking (as an ingredient) and tea-making • External use – production of essential oils Mentha × piperita Points to Note • Given the invasive nature of its underground rhizomes, Peppermint is often planted in pots to prevent the plant from growing rampant like weeds. • After the growth of the plant becomes stable, gradual pruning can be performed to improve ventilation. • Harvesting should generally be done in the morning before Peppermint blooms. • Additional fertiliser, especially nitrogen, should be applied as appropriate after harvest. • The plant is not suitable for use or consumption by pregnant women. Mentha × piperita Sweet Marjoram Scientific Name: Origanum majorana Common Names: Sweet Marjoram, Marjoram, Knotted Marjoram Family: Lamiaceae (Labiatae) Genus: Origanum Place of Origin: The Mediterranean coast Distribution: Europe, Turkey and North Africa Origanum majorana Characteristics • A perennial herb • Usually grown as an annual in cold regions • Suitable for planting all year round in Hong Kong Origanum majorana Growth Habits and Care • Sweet Marjoram thrives in a dry and warm environment with full sunlight. • It grows best in well-drained and slightly chalky loams with rich organic matter. • A wet and cold climate is not conducive to the growth of this frost-intolerant plant. • It is drought-tolerant. • If the soil in the pot is soggy or waterlogged, the plant will grow poorly and the roots may even rot. Origanum majorana Propagation • Mainly by cutting Origanum majorana Prevention and Treatment of Pests and Diseases • Sweet Marjoram rarely suffers from pests and diseases. • If it is grown in soil that is over-watered or too wet, the roots may rot, causing the plant to wilt. • Infestation and infection can be prevented by keeping the environment clean and well-ventilated. Origanum majorana Horticultural Application and Economic Value Sweet Marjoram has wide applications: • Horticulture – most suitable for cultivation in gardens or on rooftops • Medicinal use • Culinary use – cooking (as an ingredient or sauce) • External use – production of essential oils and beauty enhancement Origanum majorana Points to Note • Sweet Marjoram should be brought indoors during cold snaps in winter. • Keep it in a well-ventilated and properly shaded place to prevent the leaves from being burnt in the scorching heat of summer. • Harvest the stems by snipping them at 10 to 15 cm from the ground before flowering. • Additional fertiliser, especially nitrogen, should be applied as appropriate after harvest. • The plant is not suitable for use or consumption by pregnant women. Origanum majorana Lemon Balm Scientific Name: Melissa officinalis Common Name: Lemon Balm Family: Lamiaceae (Labiatae) Genus: Melissa Place of Origin: Uncertain Distribution: Once widely grown in the eastern Mediterranean region; now grown throughout southern Europe, Asia and other parts of the world. Melissa officinalis Characteristics • A perennial herb • While Lemon Balm is tolerant of low temperatures, it stops growing in winter. • It is suitable for planting all year round in Hong Kong. Melissa officinalis Growth Habits and Care • Lemon Balm thrives in areas with full sunlight. • The plant prefers partial shade in hot summer. • It grows best in well-drained loam containing organic matter. • Adequate soil moisture is essential for its proper growth. Melissa officinalis Propagation • Lemon Balm can be propagated by seed sowing, cutting or division. • To sow, simply sprinkle the tiny, light-loving seeds over the surface of the soil. Melissa officinalis Prevention and Treatment of Pests and Diseases • Lemon Balm has no serious pest or disease problems. • It is susceptible to diseases if light penetration or ventilation is poor. • Pay attention to ventilation and prune as necessary. • If pests or diseases are found, remove the infected parts and apply appropriate insecticide or fungicide immediately. Melissa officinalis Horticultural Application and Economic Value Lemon Balm has wide applications: • Horticulture – most suitable for cultivation in gardens or on rooftops • Medicinal use • Culinary use – cooking (as an ingredient) and tea-making • External use – production of essential oils and beauty enhancement Melissa officinalis Points to Note • Frequent pruning can improve ventilation and, more importantly, encourage development of new buds bearing leaves with a stronger fragrance. • The herb grows fast and should be planted in pots to avoid affecting other plants. • Harvest the leaves before flowering. • Apply additional fertiliser, especially nitrogen, as appropriate after harvest. • The plant should not be used or consumed by pregnant women. Melissa officinalis Information leaflets on the herbs and the relevant presentation materials will be uploaded to the following web page in due course: • http://www.lcsd.gov.hk/en/green/education/ greeningschool/plant.html Peppermint Sweet Marjoram Lemon Balm Mentha ××× piperita Origanum majorana Melissa officinalis.