Lemongrass is easy to grow in a conservatory, greenhouse or polytunnel and will be ready to harvest within 3 months. The edible part of lemongrass is at the base of the plant - the stem swells into a small bulb, roughly a ¼ inch across.
You can start lemongrass from seed or grow it from stems bought at the grocers or supermarket.
Growing from a stem
This is the easiest way to propagate new plants.
- Choose firm, green stems - ideally the stem should have a small amount of root still attached to the base.
- Shave the base of the stem with a sharp knife and insert into a 3 inch pot of good quality potting compost. Cuttings need as much light as possible and should be fine on a sunny windowsill if kept above 10 oc. Roots will appear in around 3 weeks.
- Alternatively the stems can be placed inside a Hydropod Cuttings Propagator which will produce roots in around 1-2 weeks.
- Once roots are 5cm long the plants are ready to be potted on - lemongrass will grow in any size pot (the roots will grow to fill the pot) however those grown in smaller pots will need to be divided and re-potted sooner (see plant care section for more information). We plant lemongrass in a Rain and Drain Exotics Planter, as it mimics the watering of a tropical environment.
- Tip: Be careful when handling the plant as the long leaves have sharp edges.
Starting from seed
- Using seed trays, make shallow 0.5cm deep furrows in the surface of a good quality, moist compost and sow the seeds (we always sow a few more than we need). Cover the seeds with sieved compost.
- Lemongrass grown from seed needs to be kept in a heated propagator at 20-25oc until germinated, which can take up to 40 days.
- Once the seedlings are 3 inches tall, pot them on into a 6 inch pot and grown on a sunny windowsill.
Lemongrass likes a rich, well drained environment with as much light as possible. It is a versatile plant which is happy growing on a sunny windowsill or outside, however it won’t like temperatures below 8oc, so will need to be dug up and overwintered indoors. Plants grown in the ground can reach 1 metre high, but will grow significantly smaller if grown on a windowsill.
Lemongrass is a thirsty plant that will grow best in a free-draining environment. Use a good quality multipurpose compost and a balanced such as Nutrigrow. The plant is clump forming so rather than developing its roots downwards it will spread horizontally, increasing the size of the plant. Although the roots are fairly shallow, the width of the pot will dictate how often the plant will need to be re-potted. Once the plant has filled the pot, remove the root ball and split into multiple parts by using a sharp spade or saw. As long as each piece of the root ball has at least 1 stem and an inch of root it will make a new plant. This keeps the plant healthy by preventing overcrowding and gives a supply of new plants.
Lemongrass is high in essential oils, which means that many of the traditional pests will rarely attack a lemongrass plant, however slugs and snails will often hide inside the tightly wrapped curls of leaves for protection.
Lemongrass stems are ready to harvest once the bases are ¼ thick. To harvest - cut the stem as close to the root as possible with a sharp knife. The swollen part of the stem is usually prepared and used in Thai and Malaysian cooking and the leaves are great for brewing in boiling water to make a tea.
Tips for your harvest
Lemongrass can either be worked into a paste using a pestle and mortar or sliced and added to dishes. Whole stems can be added to stews and roasts to infuse dishes with flavour (but remove the leaves prior to serving). To make lemongrass tea: cut the leaves into 2 inch pieces, place in a teapot and add boiling water. Steep for up to 15 minutes and add honey to taste.