Aubergine: profile & plant care

Regina
Regina
Regina
Regina

I studied horticultural sciences at university and in my free time you can find me in my own patch of land, growing anything with roots. I am particularly passionate about self-sufficiency and seasonal food.

Favourite fruit: quince, cornelian cherry and blueberries
Favourite vegetables: peas, tomatoes and garlic

Aubergines originate from warm tropical regions. But with the introduction of new cultivars, they are becoming increasingly popular in the garden or on the balcony. Here is everything you need to know about propagating and caring for aubergines.

Aubergines growing on plant
Aubergines are particularly heat-loving vegetable plants [Photo: J.A. Johnson/ Shutterstock.com]

Aubergines (Solanum melongena), like tomatoes (Solanum lycopersicum), belong to the nightshade family (Solanaceae). Also known as eggplant or melanzani, the aubergine is a heat-loving plant that is increasingly being grown in gardens, as well as on patios and balconies. Read on to discover everything about the plant, including where it comes from and how to successfully grow and care for it at home.

Aubergine: origin and characteristics

The aubergine originally comes from the tropical regions of Asia. According to archaeological records, has been cultivated for over 4000 years. This popular vegetable has been grown in Greece and Italy for about 500 years, after it first arrived in Europe in the 13th century. The main growing countries today are China, the USA, Turkey, Italy and Spain.

Aubergines grow into bushy, branched plants. They grow large, softly hairy, slightly lobed to wavy leaves, which can have sporadic spines on the back. Aubergine leaves are light green to violet-green with dark leaf veins, depending on the variety and species. The plant’s root system is somewhat shallower than that of the tomato, but the main shoots are much woodier in comparison. From June onwards, the plant’s large, mostly purple or white, star-shaped flowers appear on the inflorescences. These usually develop into one or two fruits per inflorescence, which can be oval, round, bell-shaped, club-shaped or elongated. As they ripen, their skin usually turns dark purple or white, but purple-striped, yellow, orange or green fruits can also develop. Inside, aubergines have a creamy white flesh with many plump red-brown seeds.

Aubergine cultivation
Aubergines, like tomatoes, belong to the nightshade family

Is the aubergine a fruit or a vegetable?

The aubergine looks unusual. As a result, many people are perplexed as to what it is. In fact, there is no precise definition of fruit and vegetable; the aubergine, for example, is commonly referred to as a fruiting vegetable. Botanically speaking, the fruits are berries. However, as aubergines contain hardly any sugar and are therefore not used in cakes or jams like fruit, they are more commonly classified as a vegetable. Find out how to store and process aubergines properly in our article on harvesting and storing aubergines.

Are aubergines perennial?

Aubergines are essentially perennial plants. However, as they have no frost or cold tolerance and usually die in winter, they are grown from seed every year in cooler regions. In theory, overwintering is possible, but he effort and the high risk of pest infestation during the winter months are not worth it given how easy it is to grow new plants.

How tall do aubergine plants grow?

The plants reach an average height of 70 to 150 cm. Meanwhile, aubergine varieties with an extremely bushy growth of up to 40 cm and small fruits are also available, making them ideal for growing in pots and on balconies.

small aubergine with flowers
Aubergines can be dwarf small or grow up to 150 cm tall [Photo: Max_555/ Shutterstock.com]

Aubergine plant care

Aubergines are like tomatoes when it comes to the amount of care they require. Once they are fully grown, however, they will reward you with a rich harvest of their versatile fruits. Here are our tips on how to care for aubergine plants.

Fertilising and watering

Aubergines are among the most nutrient-hungry, high-yielding vegetables. Fertilising aubergines is therefore an important care measure to keep the plants healthy and productive. Slow-acting, natural fertilisers release their nutrients over several months to years, improve the soil structure through decomposition and serve as food for soil organisms. In spring, work mature compost or manure into the bed or greenhouse. A liquid fertiliser such as our Plantura Liquid Tomato Food, can be used on aubergine plants that are grown in pots as well as outdoors. Apply the fertiliser about once a week in a dosage of 5 to 15 ml per 5 litres of water when watering. The essential nutrients contained, such as potassium and nitrogen, reach the plant roots directly. Even signs of acute nutrient deficiencies, such as a yellowing of the lower leaves, can be quickly cured in this way.

Liquid Tomato Food, 800ml
Liquid Tomato Food, 800ml
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Aubergines need quite a lot of watering – in summer, water daily, preferably in the morning. Never water the plants from above because this harms the fruit and shoots. Also be careful not to let water spray dirt onto the leaves as this can spread pathogens. To avoid the spread of any pathogens, water aubergine plants at the base directly onto the stem.

aubergine plant with nutrient deficiency
A lack of nutrients is usually first noticeable on the older leaves

Pruning aubergine plants

You do not have to pinch out aubergines, but there are some benefits from doing so. By only growing two to three main shoots and regularly removing all other side shoots, the plant has more energy to produce fruit. In addition, plants growing in greenhouses with high humidity, dry out more quickly thanks to being pinched out. They are therefore less at risk of suffering from fungal diseases. In the case of small-growing mini aubergines for the balcony, no pruning is necessary, as the small fruits are usually sufficiently supplied. However, to stimulate flower formation, you can break off the first flower – just like with peppers.

aubergine vegetable with grey mould
Weakened aubergine plants can be affected by grey mould if the humidity is high [Photo: iztverichka/ Shutterstock.com]

Aubergine plant problems

All of the diseases and pests that can affect tomatoes can also affect aubergines. Surprisingly, pests such as aphids and spider mites prefer aubergines over all other plants in the greenhouse. So much so that it is used as a kind of trap crop for pest control in some nurseries. When the plants become infested, it is considered a sign that the entire crop should be treated as a precaution. Aubergines are susceptible to the following diseases:

  • Aphids (Aphidoidea): In case of heavy infestation, they lead to deformed and curled leaves and shoot tips.
  • Spider mites (Tetranychidae): The leaf-sucking arachnids lead to characteristic, punctiform lightening and small webs on the plants.
  • Whitefly (Aleyrodidae): Small white flies feed on sap and excrete sticky ‘honeydew’ all over the plant, promoting the growth of sooty mould. Adult whiteflies are often the first to be noticed, as they fly up when the plant moves.
  • Colorado potato beetle (Leptinotarsa decemlineata): The larvae of the Colorado potato beetle feed on the foliage often leaving behind just a leaf skeleton in a very short time.
  • Grey mould (Botrytis cinerea): Fungal disease that likes to infect injured and weak plants and flowers as well as fruits in warm and humid conditions. Initially brown spots form, which are later covered by fuzzy grey mould.
  • Fungal wilt: Fungal disease, for example caused by Verticillium or Fusarium oxysporum, whereby the lower leaves first turn yellow and the entire plants subsequently wilt. The conduits for water and nutrients are discoloured brown.
seeds in sliced aubergine
To extract the seeds, aubergines are harvested late – the seeds are now already brown [Photo: Claudio Divizia/ Shutterstock.com]

Propagation: collecting aubergine seeds

You can collect seeds yourself to propagate aubergines. All non-hybrid, seed-producing types can be propagated true to type. Aubergines usually self-pollinate – gently shake the open flowers in the morning to help.

Now it is a matter of waiting until the fruits and the seeds inside have ripened. To collect the seeds, you will need to let the fruit ripen much longer than you generally would for consumption, frequently until just before the end of the season. A sure sign that the seeds are well ripened is the further colour change of many fruits from the ‘harvest colour’ to the ‘ripe colour’, such as white to yellow, purple to brown-purple, or yellowish-green to orange-red. The skin becomes tough and firm. The seeds inside are brown, have a hard shell and can be removed from the flesh easily with a knife. Now wash and dry the aubergine seeds at room temperature. Store in a cool, dry, and dark place and the seed will be able to germinate for about four years.

Once the seeds have been collected, it is time to sow the aubergine. In our article on planting aubergines, you can learn everything about sowing the seeds and planting out aubergine seedlings.