If you’ve ever tried to purchase a Christmas stocking-filler for a liquorice-lover, you’ll know that there is a bewildering diversity of options to enjoy. From black liquorice wheels to liquorice allsorts to Pontefract cakes – even a highly salted liquorice confection favoured in Nordic countries - there is a liquorice for everyone. If you like liquorice, that is. Plenty (me included!) don’t.
But interestingly, liquorice extract is taken from the root of a plant that can easily be grown in many areas (not to be confused with the liquorice plant, Helichrysum petiolare, which is not edible). By all accounts true liquorice root (Glycyrrhiza glabra) tastes a world away from the sugary processed sweets available in the shops, which are often laced with anise and other flavourings. Considering how strongly liquorice fans feel about their favourite culinary indulgence, it seems strange that the real deal isn’t more commonly grown.
When you realise how long it takes to achieve a harvest of liquorice, the reason it is not more popular becomes clearer. Commercially, liquorice plants are not harvested until they are four or five years old. However, in the home garden it is possible to take a small harvest after three years – about the length of time it takes for your first harvest of asparagus.
But it you have the patience the rewards are worth it. Growing from seed isn’t especially difficult but germination can be erratic, so it’s worth sowing extra in case of failures. Sow seeds on the surface of potting compost in mid to late spring or early autumn. Don’t cover them. Keep them warm – about 20°C (68°F) – and with any luck, two or three weeks later your liquorice seedlings should have popped up.
Alternatively, you may be able to source one- or two-year-old plants. Liquorice will send up new shoots from spreading underground stems, known as rhizomes, from its second year. These can also be cut off and used to grow new plants.
Liquorice is fairly hardy once established, so in most regions it can be planted out once the last spring frost has safely passed. In really cold regions it may be best to plant in a container and bring it into a greenhouse or other sheltered place for winter, but make it a deep pot because liquorice has very long roots!
Liquorice Growing Conditions
While liquorice is slow to get going, it has the potential to become quite large after four or five years – up to two metres (six feet) tall, with a spread of about a metre (three feet). If you’re planting in a flowerbed make sure to leave plenty of space around the plants for digging up the root. With its violet or pale blue flowers and ferny foliage liquorice makes an attractive plant for the back of the border, so this isn’t as crazy as it may sound! You could always plant shallow-rooting summer annuals like marigolds around it.
A riverbank plant by nature, liquorice likes plenty of water and sunshine. Avoid windy spots and frost pockets. Sandy soil is a must. If your soil is very heavy, prepare it before planting. Dig a pit at least two spits wide and deep (a spit is the length of a spade blade). Remove any stones, mix the soil with lots of compost and fill it back in.
Liquorice is a legume, and like other legumes it fixes nitrogen at its roots so rarely needs additional fertiliser. It will, however, appreciate occasional mulching to help keep weeds down and retain moisture while at the same time providing extra nutrients. Never let the soil dry out.
Slugs, caterpillars and spider mites can be a problem, and the plants can suffer from powdery mildew. Protect them from rabbits too. Otherwise liquorice is pretty trouble-free.
When it’s finally time to reap your just rewards, dig up your liquorice root plant. The roots are brownish-yellow, long and flexible, with a yellow, juicy interior. Harvest the thickest horizontal roots but leave the deep tap root and thinner horizontal roots to grow on. Replant or bring it under cover for winter in very cold areas.
Chewed fresh, the root tastes sweet and a little salty. The sweetness intensifies the more you chew and release the sap. Liquorice can be used for flavouring a wide array of sweets, dishes and drinks. The roots can also be dried for later use in teas and baking. Try keeping a root in a jar of sugar to flavour cakes with.
Make sure to harvest it each year, because if left unharvested liquorice roots can reach startling lengths. Four metres (13 feet) is common, and eight metres (26 feet) is not unheard of. Try untangling that from your flowerbed!