With its rich mix of flavour and textures, Thai cuisine has been steadily gaining a loyal following in Britain. Shoppers can now find an increasing range of both fresh and processed Thai ingredients, while restaurants can be found in the most unlikely towns.
Seed companies and nurseries are serving this trend, selling a helpful selection of herbs and vegetables suitable for Thai food. They include the exotic as well as the familiar, and there is enough variety to satisfy the plate of even the most adventurous gardener.
Because of this variety, the plants used in Thai cooking do not conform to any one particular growing regime. Though many will thrive in a well-prepared garden soil, most do just as well in a container with the right compost. Considering Thailand’s tropical location, it is not surprising that many are better adapted to summer growing, either outside or in the protected environment of a polytunnel or greenhouse. Growing and cooking Thai, however, is not just a summer activity, and other ingredients are well adapted to growing during colder times of the year.
Without the heat from chillies, Thai cooking simply would not be the same. They are so important that Thai shops sell at least eight distinct varieties, varying from the small, hot prik kee nu (Capsicum frutescens) – which translates as ‘mouse dropping chilli’ – to the larger, milder prik yawk (C. annuum).
Culinary purists striving for authenticity can try extracting seed from shop-bought chillies, but there is a slight risk of importing seed-borne diseases into the garden, and it may be safer to buy seeds and plants from a reputable source.
Fortunately, chillies do not have to be ‘strictly Thai’ to work in a recipe. The variety Hungarian Hot Wax is a good substitute when a larger, vegetable type chilli is needed, while Super Tramp, Rooster Spur and Tabasco are ideal when small-fruited, pungent chillies are required.
Although they play a secondary role to chillies, aubergines are a key ingredient and display a diversity of shapes, sizes and colours. Long, thin ones that come in both purple and green are popular either stir-fried or grilled, and gardeners wanting to grow them can try the varieties Pingtung Long and Thai Green. In contrast are round, green-and-white ‘apple’ aubergines such as Kermit. They have a crunchy texture and are eaten raw with dips or cooked in curries.
Being tropical, Thai cuisine often combines naturally with citrus flavours. One source is kaffir lime, a citrus tree with aromatic leaves extensively used in Thai recipes. Though kaffir limes can be grown from seed taken from shop-bought fruit, they are so slow growing that gardeners may prefer to buy nursery-raised stock. The plants are suited to growing in pots, doing best in well-drained compost kept at pH 6.5. They also need regular feeding, preferably with a special citrus fertiliser high in trace elements.
During summer kaffir limes can be kept in polytunnels, greenhouses and conservatories, provided they do not overheat and humidity is maintained around the plants. In the winter keep them in cool, dry conditions (minimum 7 degrees C), and be sure to protect the plants from freezing.
Another source of citrus flavouring is perennial lemon grass. Because the Thai species does not flower, it must be propagated from vegetative material. This is simpler than it sounds, since the stems (‘tillers’) sold for cooking will root if they are stuck into moist compost or a glass of water and bottom-heated to about 27 degrees C. After the stems have rooted they can go into a large pot and be grown in the warmth of a polytunnel or greenhouse. Keep plants indoors over winter to avoid freezing temperatures.
To harvest, individual stems are cut off at soil level. The lower part is used in curry pastes and soups, while the leafy tops can be made into a delicately-flavoured tea.
Thai cooks create dishes with big, robust flavours, aided to a considerable extent by the addition of herbs. Basil is often used, and Thai shops sell a selection under the names ‘lemon’, ‘holy’ and ‘sweet’. If only one type is grown, however, it should be a sweet one such as Siam Queen. Tasting like anise, this variety is culinary the most useful.
Coriander, too, has favoured status with the Thais, who use not just the leaves but the roots as well. It is an annual that quickly (and frustratingly) goes to seed, at which point leaf production stops. To extend the harvest period, varieties that have some bolt resistance, such as Santos and Calypso, should be used. Successional sowings can be made outdoors from early spring to early autumn. Plants can also be grown throughout the winter in a polytunnel or greenhouse, though their flavour will be rather bland.
While sticking close to its traditional roots, Thai cuisine also welcomes new ingredients. Oriental vegetables such as pak choi have been adopted by the Thais, while innovations closer to home have included spring greens – stir fried with oyster sauce – and rhubarb used in place of tamarind in kaeng som, a sour fish and vegetable soup.
Anyone interested in Thai food will quickly come across som tam thai, a salad made with shredded green papaya, but papaya can be replaced with garden grown carrots, kohl rabi or turnip. French beans can take the place of yard-long beans that would usually be used, and once essential chillies, garlic and cherry tomatoes are added, the new version is as full-bodies as the Thai original.
The Thais are promiscuous eaters, and a comprehensive list of all the vegetables and herbs used in their cooking would seem almost endless. So for the adventurous kitchen gardener there are plenty of plants of interest to make growing and cooking this exotic cuisine a challenging, life-long pleasure.
Other Thai Vegetable and Herbs for Gardeners
A heat-loving plant, the fruit of which are steamed and served with dips.
• Water Spinach
Called ‘morning glory’ by the Thais, this trailing plant is grown for its tender tips and leaves that can be stir fried. Grow in polytunnel or greenhouse and keep moist.
• Vegetable amaranth (calaloo)
A relative of love-lies-bleeding, its stems and leaves are used in stir fries and curries. Thought it may grow outdoors in the mildest areas of Britain it is more of a polytunnel or greenhouse crop.
• Baby corn
An especially tender treat, but there is no need to grow a maize crop just for its baby ears. Instead, when growing a normal sweet corn crop, just harvest the secondary ears on each stem, just as the silks emerge from the surrounding leaves, leaving the primary ears to grow into corn-on-the-cob..
An indoor climbing plant with a ‘slippery’ texture that may be off-putting. The stem tips and flower buds are cooked in stir fries and curries.
The small, red Thai types are eaten both raw and cooked, but as with garlic, Western varieties available to gardeners work just as well.
• Bitter melon
Something of an acquired taste (its name says it all). Sprawling, heat-loving cucurbits, they have the same cultivation requirements as indoor cucumbers.
• Dill and mint
These two herbs are well suited to Thai cooking. Dill is started from seed, but mint is started vegetatively – shop-bought stems can easily be rooted if you don’t know a friend growing mint.
• Vietnamese coriander
A powerfully-flavoured, pungent herb easily propagated from shop-bought stems rooted in a glass of water. Keep plants in a polytunnel or greenhouse.
An essential ingredient, the Thai versions are diminutive copies of those grown in the West. Despite the difference, Western varieties are adequate substitutions.
- Thai Food, by David Thompson, Pavilion Books, 2002, ISBN no. 1862055149.
- Growing Unusual Vegetables, by Simon Hickmott, Eco-Logic Books, 2004, ISBN no. 1899233113
- Grow Your Own Vegetables, by Joy Larkcom, France Lincoln, 2002, ISBN no. 071121963X
- Success With Citrus, by Patricia Oliver,Global Orange Groves UK, 1993, ISBN no. 095224960X
© Michael Michaud