Thai aubergine: planting, caring & harvesting
Thai aubergines are related to the dark purple veggies we are used to, but they have a distinct appearance and flavour. Luckily, growing and taking care of them is very similar to all other types of aubergine.
Look no further if you want to grow a new and exotic type of vegetable in your garden. Read on to find out more about growing Thai aubergines, from sowing and plant care to harvest and uses of this unique vegetable.
Contents
Thai aubergine: origin and properties
Thai aubergine refers to a variety of aubergine plants, including:
- Several varieties of the common aubergine (Solanum melongena) that are primarily used in Thai cuisine and are therefore referred to as a Thai aubergine.
- The species Solanum xanthocarpum (or Solanum virginianum) is also known as Thai green aubergine. Kantakari is the common name for this species in Asia, and it is also known as yellow-fruit nightshade, thorny nightshade as well as Thai green eggplant in the UK.
Thai green aubergine is usually grown as an annual and has green or yellow golf ball-shaped fruit. As the name suggests, the plant is native to Southeast Asia, where it likes to grow near water. The herbaceous Kantakari plants are bushy and can grow to be up to 80 cm tall. The stems and leaf veins are extremely thorny and the large, lobed leaves are approximately 5 – 10 cm long.
Around July, Thai green aubergines begin to bloom stunning violet flowers, which attract insects before developing into small fruits. The fruit has several bitter compounds that make it mildly poisonous until it ripens. Thai aubergine seeds are widely available in the UK.
Tip: If you keep your mini Thai aubergine plant in a bright, warm spot during winter, it can live for several years.
The unusual varieties of Solanum melongena called Thai aubergines do not necessarily look like aubergines at first. The ‘Thai White Ribbed’ is particularly striking with its shiny, porcelain-coloured fruit. Likewise, the ‘Thai Long Green’ boasts 30 cm long, slightly curved green fruit with a powerful and slightly sweet aroma.
Find out all about the different varieties of aubergine here.
Planting Thai aubergines
Growing and planting Thai aubergines is quite similar to growing and planting standard aubergines. More thorough instructions and tips can be found in our article on planting aubergines.
Thai aubergines require a lot of heat and can only live outside from mid-May onwards, so start them indoors from March to early April. Here’s how:
- Fill small pots with moistened, low-nutrient soil, such as our Plantura Organic Herb & Seedling Compost.
- Sow one Thai aubergine seed about 1 cm deep in each pot.
- Moisten the soil again and place the pots in a bright, warm spot at around 20 to 25 °C. Place the pots in a mini-greenhouse or cover the pots to provide high humidity and warmth.
- The seeds will germinate after one to three weeks; continue to keep them warm and well-watered until the first true leaves appear.
- Transplant seedlings into larger pots with a nutrient-rich substrate such as our Plantura Organic Tomato & Vegetable Compost, which meets the aubergine’s high potassium requirements and is specially developed for heavy feeders.
Tip: From day one, Thai aubergines need a lot of water. Water them regularly, but carefully and via their saucers, if possible. Aubergine plants are susceptible to damping off, a disease caused by fungi that thrive when the soil’s surface remains damp.
- Perfect for tomatoes & other vegetables such as chillies, courgettes & more
- For strong & healthy plant growth as well as an abundant vegetable harvest
- Peat-free & organic soil: CO2-saving composition
In mid-May, the Thai aubergines can be transplanted to their intended location. Choose a moist, sandy spot that is sufficiently warm and sunny, with neutral to slightly acidic soil. At night, temperatures should not go below 15 °C. Grow the Thai aubergines in a greenhouse, foil tunnel or under protective netting to keep them warm and humid and get a better yield. Make sure to space the plants 50 – 60 cm apart. Since Thai aubergines are heavy feeders that require a lot of nutrients, enrich the soil with mature compost or our Plantura Tomato Food before planting them. Thanks to its long-lasting effect, our fertiliser will keep your aubergines well-fed throughout the entire growing season.
Tip: When choosing a location, consider crop rotation and companion plants. Keep a four-year gap between aubergines and other nightshade crops like tomatoes, peppers, and potatoes. Garlic (Allium sativum), carrots (Daucus carota subsp. sativus) and calendulas (Calendula officinalis) all make excellent companion plants for Thai green aubergines.
When planting Thai green aubergines in pots, choose a container with a volume of at least 10 litres and drainage holes. Fill with a nutrient rich growing medium, such as our Plantura Organic Tomato & Vegetable Compost. Like all our composts, it is peat-free and considerably more sustainable than conventional composts. Place your aubergine pots in front of a warm and sunny south-facing wall.
Caring for Thai aubergines
Water and fertiliser
Aubergines need consistently moist soil and do not tolerate drought. Water the plants at least two to three times a week if there is no rain. You may even need to water potted aubergines daily. While watering, keep the leaves dry to prevent fungal infections and other damage.
Tip: Mulching aubergines is advantageous since it helps to retain soil warmth and moisture. Mulch your aubergines with grass clippings or straw.
Thai aubergines require slightly fewer nutrients than classical aubergines due to their smaller fruit size. If you plant them in well-fertilised soil, you will not need to fertilise them as frequently during the growing season. For example, add our Plantura Liquid Tomato Food to your watering can once a month. Our liquid fertiliser is simple to use and animal-free.
- Perfect for tomatoes & other vegetables
- Liquid fertiliser for healthy plant growth & an abundant harvest
- Quick & easy application - child & pet friendly
Pruning Thai aubergines
Most Thai aubergine plants do not need to be pinched out, as they bear very small fruit and usually have enough energy for all of them. Leave a maximum of two to three shoots on plants that are growing large fruit. Pruning the Thai aubergine improves ventilation and lowers the risk of some fungal diseases. Stake Thai aubergine plants that are bearing heavy fruits.
Common diseases and pests
Unfortunately, Thai aubergines are susceptible to many diseases and pests. These include aphids (Aphidoidea), spider mites (Tetranychidae), potato beetles (Leptinotarsa decemlineata), whiteflies (Trialeurodes vaporariorum), leaf spot disease (Cercospora melongenae) and late blight (Phytophthora infestans).
Overwintering
If you have healthy Thai aubergines in pots, you can try to overwinter them. Place them in a bright, cool place in autumn with temperatures over 15 °C. In winter, Thai aubergines need much less water. Nevertheless, do not let the substrate dry out completely until the plants can be put outside again in May.
Harvesting and using Thai aubergines
Depending on the variety and when they were planted, Thai aubergines can be harvested from July into autumn. Recognising the right time to pick them is not that easy. If the fruit is harvested too early, it still contains too many bitter components such as solanine. However, if you harvest fully ripened fruit, it will contain an inconvenient amount of seeds. Harvest the fruit once it has reached its maximum size (usually golf ball size for Solanum xanthocarpum) and you can gently dent the surface, but before they change colour.
When harvesting, use a sharp knife to cut the aubergines off cleanly. This reduces the risk of pathogens entering via the cuts.
Tip: If you have accidentally picked unripe fruit, simply leave them in a bright place to ripen for a few days at room temperature.
Many Thai eggplant cultivars can be eaten raw when fully ripe. Cooking them, for example, in a beautifully tangy Thai aubergine curry, will add nuance to your meal.
Another little-known Asian vegetable is tatsoi (Brassica rapa var. narinosa). You can use it in stir-fries, among other things, and even grow the fast-growing leafy vegetable in autumn.
