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Leisure and Cultural Services Department

Planting Herbs in School Scheme

2017/18

PeppermintMentha ×××× piperita

Sweet MarjoramOriganum majorana

Lemon Balm 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

Mentha × piperita

• 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.

Propagation

Mentha × piperita

• By division

• By rhizome cuttings

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

PeppermintMentha ×××× piperita

Sweet MarjoramOriganum majorana

Lemon Balm Melissa officinalis