Introduction

Cymbopogon is a genus of frost-tender perennial, occasionally annual, aromatic grasses. There are 56 species, one of which is citratus (lemon grass). The plants can be found growing in many tropical and temperate regions. The species citratus is mainly found on savannah in southern India and Sri Lanka. The name Cymbopogon comes from the Greek words for boat 'Kymbe' and beard 'Pogon'. This is a reference to the flower spikelets, which seldom appear when the plant is grown in cultivation. The plant forms a clump and has cane-like robust stems and thin strap-like scented leaves. Several species are grown for their oil, which is used in the perfume industry.

How to Sow for Best Results

Lemon grass can be difficult to germinate, however, just a few plants achieved from your packet of seed should more than satisfy your needs.

The compost should be moist, but definitely not wet. Wet compost (which can even be the case straight from the bag) will be cold and reduces the oxygen that the seeds need to germinate. It may even stop the seeds germinating at all. If the compost is too dry this will also cause problems. If this is the case, sprinkle a small amount of warm, clean tap water over the compost and leave it to soak in thoroughly. When the compost has absorbed the water, take a small handful and squeeze it in your fist; if water drips out it is too wet, so leave it for a short while in a well ventilated spot to dry off. If it holds together when you open your hand, its just about right. You can now fill your seed tray or pot with the moist compost and you dont have to water it again before you sow the seed.

Sow the seed from late January in a 7.5cm (3in) pot, on the surface of the compost, then cover with a very fine sprinkling of Sow Lite or free draining compost. Sow Lite is a natural mineral, (known as vermiculite) which, when exposed to very high temperatures, expands to produce a honeycomb like structure. Gardeners can benefit from this structure, as it helps to absorb excess moisture, insulates the seed and allows oxygen through the compost to the germinating seed.

The soil temperature is critical for good germination. Place the pot inside a clean, clear plastic bag and seal with an elastic band. This will help hold in the humidity and heat required. It has to be a steady 20°C-22°C (70°F-72°F). This is about the temperature of a cool, bright windowsill or an unheated greenhouse bench. The temperature must not fluctuate as this can cause poor or failed germination. Hot soil temperatures may cause the seed to become dormant, so use a soil thermometer to keep an eye on it and move the pot to a cooler location if the soil does get too hot. Seed will germinate in 21 to 40 days.

Check the compost for dryness regularly, add a little clean water from below, being careful not to over water. Too much water can kill seedlings, as it can spread 'damping off fungi' and encourage other moulds and diseases.

When the seedlings are large enough to handle, transplant them carefully into 7.5cm (3in) pots. Grow on for a few weeks in a cool, frost-free, well lit place, avoiding direct sunlight. Gradually acclimatise them to outside conditions by placing them in a sheltered place during the day and bring them back inside at night. Watch out for cold winds as well as pets, birds, mice etc. After all risk of frost has passed they can planted into their final position. This should be a sheltered spot in full sun and the soil should be moist but not waterlogged. The plants can be happily gown in containers; plant into a 25-30cm (10-12in) pot and keep in the greenhouse, conservatory or in the summer out on the patio. During the summer keep well watered and feed occasionally with a general purpose liquid feed.

The plants are frost tender so, if grown outside, the plants must be lifted and potted up in early autumn, before the first frost. Keep the plants in a greenhouse or conservatory at a minimum temperature of 7°C (45°F) throughout the winter. The plant may be propagated by splitting in early spring.

To harvest lemon grass, cut the stems at ground level and use fresh in Thai and Vietnamese cooking. The leaves can be used as an infusion as tea. It is said to increase perspiration and relieve spasms and be effective against many fungal and bacterial infections.

Caution

If taken internally, in excess may cause nausea and vertigo. Large doses should never be taken by pregnant women or very young children. Care should also be taken by persons with heart or lung disease.

The above information is intended as an illustration of the uses associated with this plant. On no account should this information be used as a guide to self treatment. Any such intention should be undertaken with the strict guidance of your GP and/or a qualified herbal practitioner/homeopath. Thompson & Morgan will not be held responsible for any loss or injury caused by failure to observe this caution.