Lars Lund

26 Jan 2023 11:14

Grow aubergines: the blue ruby of the greenhouse

The blue ruby of the greenhouse 

How to successfully grow aubergines in your greenhouse

You do not need to travel the world for 80 days to grow aubergines, but it takes around 80 days for you to harvest the exotic fruit, that is often an important ingredient in a Greek moussaka or in a French ratatouille.

The aubergine is not nearly as popular to grow in the greenhouse as cucumber or tomato, which is a huge shame. This kind of mushy fruit, which biologically actually is a berry, is both healthy and tasty. It is just as easy to grow as tomatoes and cucumbers. The only requirement it has, that separates it a little from the other fruits, is the amount of heat. It is therefore best to grown it in the greenhouse.

The nightshade family

Like the potato, the aubergine is from the nightshade family and that means parts of the plant are poisonous. Green potatoes are poisonous and aubergines, which have not been treated with heat are as well. The same goes for the leaves and flowers. Therefore, you must always for example cook or fry the fruit.


Growing in pots

You are more than welcome to grow your aubergines in a growing bag or a bed in your greenhouse, however, in many ways the aubergine is more suited for pots. The soil in pots is getting warm faster, and because the aubergine is perennial, like the chili, you can take the pot with your plant inside during the winter, and you don’t have to start all over next year.


Begin late in February

The seeds are available now and there are several different sorts. Some become quite big, both the plant and fruit, while others are smaller. Most people prefer the smaller sorts because they produce many fruits. Start by sowing them in a little pot. The seed only needs to be place one centimeter below the soil. Use potting soil. Place them in a warm spot, maybe with a heating mat under. They require at least 21 degrees, but it is best at 25 degrees. When they have sprouted after approx. 14 days, they need full sunlight. Repot them when they start to grow and are about 10cm tall. When the roots completely fill up a 12 cm pot, they should go over into a bigger pot.


Hardening off

Just like chili and cucumber plants, don’t put the aubergines outside in the greenhouse too early. It needs to be around 15 degrees both day and night, so in the beginning of June or maybe mid-May if the temperatures allow it. You can harden off your aubergines slowly by putting them in and out during the first week. Be especially aware of the temperature during the night. It should not be a lot under 15 degrees. If that happens, cover the plants with a fibre cloth.  Don’t let the aubergines stand in the shade of other plants in the greenhouse. They need sun, sun, and more sun. When the fruit grows, it can become quite heavy, and therefore it can be useful to tie up the fruit, so it gets support.


Water and care

Water with tempered water and fertilize like you do with tomatoes. Pick off the first flowers, so it grows more and seeds more fruit.  Help the pollination by using a brush.



Harvest the aubergines when they feel firm and have a blank surface. Typically, that will be late July and start August. If they become overripe, they will be soft and have a lot of seeds. Remember to grill them or roast them in an oven or pan before you eat them. Otherwise, your stomach will probably hurt. If they taste bitter, it is because of old genes re-emerging. In that case, you can cut them into slices, salt them, and then let them sit for about 30 mins.



Aubergines easily get lice. Therefore, it is an advantage to grow the aubergines in pots. That way, they can be taken out of the greenhouse before they infect other plants. Spider mites are a rare occurrence, whereas snails do not have a problem tackling the aubergine.


Different varieties

The Latin name of the aubergine is Solanum melongena. Not all sorts become purple or like a ruby, som might be green with stripes or white like eggs.

  • Ping Tung Long Wer, is an Asian sort, with the classical long fruits.
  • The sort Mini Stiped Toga is among the smaller plants that become around 50 cm tall. They get orange/green stripes and mature in august.
  • Totonda bianca sfumata di rosa has delicate violet pattern inside that becomes visible when cut into slices.
  • Bianca el Uovo looks like a hardboiled egg. It has beautiful purple flowers and produce a lot of fruits.
  • Black beauty is an organic sort in the classical purple colour with a chubby pear-shape. It is among the bigger sorts with fruits at become 10-15 cm.
  • White is a beautiful drop-shaped white aubergine with a mild flavour.
  • Fengyuan Purpe almost looks like blue beans. It Is easy to take care of.