Lemongrass is one of my favourite tasting herbs, and one that I never thought I would grow at home. I use it when cooking Thai dishes and it's just divine in a Tom Yum Soup served with a side of jasmine rice. Its lemony-ginger taste is also delicious as a refreshing tea, a cup of which I'm enjoying at the moment :)
Lemongrass is commonly grown from seed in the UK, and you can buy a packet of them for around £1.50. However the seeds are quite small and fiddly and the germination rate can take up to 40 days, which is a lot of time for most people to keep a small tray of soil moist and in the correct temperature. A quicker way to grow lemongrass at home is from bulbs, either purchased in a garden centre or in the supermarket. When I say supermarket, I mean the lemongrass that's sold for consumption opposed to growing as plants. Lemongrass in the shop will run you about 99p for a small bundle and if it's not wilted or too brown/dried-out, it's possible to grow a new Lemongrass plant from each stalk!
To get started, go shopping and buy the firmest, least dried out bunch of lemongrass you can find. Take it home and then peel back the first layer or two and a good part of the upper leaves, especially the ones which are dried out.
Then fill a glass with plain water, put your trimmed lemongrass stalks in and place the whole thing into a warm window sill. The water should completely cover the bulbous bit at the bottom of the stalks. Within a week or two, roots will start to appear and possibly some leaves. When the roots are about 1-2 inches long, you can trim back the original stalk a bit more and then plant each stalk into its own small pot of compost. Gently cover all the roots and quite a bit of the bulbous part at the bottom if you can. One of my stalks sprouted some baby leaves though so that one I just made sure to cover the roots and a bit of the bottom of the bulb. As soon as the leaves are bigger, I'll add more compost to the pot.
These small pots of lemongrass should be grown on in a warm place until they have plenty of leaves and the roots need a bigger pot. At this point, you can harden them off over a week and then plant outside in a sunny, warm and moist spot 12 inches apart. You can also re-pot them on into larger containers to keep indoors or in a greenhouse. Fully grown, the plant is fairly bushy with long thin leaves and numerous stalks emerging from the original one. Though they can grow to large sizes if they have the space, a container or pot will constrict their roots enough to make it a lovely house plant.
To harvest, just select the stalks you want and simply break them off the main plant at the base. The bulb is the bit you mainly use in cooking and it is actually the only part you can eat. The leafy bits can be used as well but you'll need to pick these out at the end of the cooking time. Better yet, pop them into the freezer and use them when you want to have a nice cup of tea.
Lemongrass requires a minimum of 7°C/45°F so if you plant it outside, make sure to lift them in the autumn and bring them into a greenhouse or conservatory. And with a little luck your plant will look just as great when you plant it back out the following year :)