Aubergine: growing from seed from sowing to harvest

Sowing aubergines in warmth, planting in a greenhouse or in a bed, watering, training and harvesting. Including a table of the most common problems.

In short: Aubergine is sown from mid-February to mid-March on a windowsill at 22–28 °C. It is planted in a greenhouse in mid-May and outdoors not until June, when nights do not fall below 12 °C. Leave 5–6 fruits on the plant and harvest them glossy, while the skin still springs back when pressed.

Latin name	Solanum melongena, nightshade family
Sowing	15 Feb – 15 Mar, depth 0.5–1 cm
Germination	22–28 °C, 7–14 days (it stalls below 21 °C)
Planting	greenhouse from mid-May, outdoors from June, spacing 50 × 60 cm
Container	at least 15 l per plant
Harvest	July–September, 5–6 large fruits per plant

Of the fruiting vegetables, aubergine is the most demanding of warmth. Peppers and tomatoes will forgive you a cooler week, but aubergine stops at nights below 12 °C and drops its flowers in prolonged cold. That is why it does best here in a greenhouse or polytunnel, and outdoors only in warm regions and in a sheltered spot by a south-facing wall.

The good news is that the whole procedure from seed to harvest is simple if you stick to three things: early sowing in warmth, planting out only into warmed soil and limiting the number of fruits. Below is everything in the order it comes up in the garden.

What aubergine is and which varieties to choose

Aubergine, or eggplant (Solanum melongena), comes from tropical Asia, most likely India. It belongs to the same family as tomatoes, peppers and potatoes, so it shares their needs, diseases and pests. A more general look at the nightshade genus is in the article The aubergine is not just a healthy vegetable.

For our conditions choose according to where you will grow it:

Type of variety	Fruits	Where it suits
early, small-fruited	round or short, 8–12 cm	outdoor bed, container on a balcony
cylindrical mid-late (e.g. 'GOBI')	slender, 15–20 cm, dark purple	polytunnel, in warm regions also the field
large-fruited oval ('Black Beauty' type)	egg-shaped, 300–500 g	greenhouse, a long summer
white and striped	various shapes, thinner skin	greenhouse, more for the experienced

If you are starting out, reach for a cylindrical variety for a polytunnel. Aubergine GOBI is a mid-late variety with slender fruits 15–20 cm long, intended for polytunnels and, in warmer regions, for the field.

Sowing aubergine step by step

Roughly 5 months pass from sowing to the first harvest. Anyone who sows in April will harvest the first fruits only in September, and often just a few. The ideal date is from mid-February to mid-March; for a greenhouse you can start even earlier, for growing outdoors the beginning of March is enough.

Prepare the warmth. The seeds need at least 21 °C to germinate, ideally 25 °C. A windowsill above a radiator cools at night; a heated propagator is more reliable, for example the Garland OneTop L with a heated mat.
Fill a tray or cell tray with fine seed compost, press it down lightly and moisten it.
Sow the seeds 2–3 cm apart at a depth of 0.5–1 cm and cover them.
Cover with a lid or film and keep moist, not wet. At 25 °C the seeds germinate in 7–14 days, in the cold in up to 3 weeks and unevenly.
After emergence put the seedlings in light, ideally on a south-facing window or under a grow light. Lower the temperature to 20–24 °C by day and 16–18 °C at night, or they will stretch.
Prick out as soon as they have the first true leaf, into pots 8–10 cm in diameter. After another 4–6 weeks you can move them into 12 cm pots.

If you have no space by the window, you can raise aubergines in a mini propagator with ventilation. More about what is sown on a windowsill in February is in the article What to sow in February.

Planting in a greenhouse, in a bed and in a container

A seedling is ready when it has 5–7 leaves, is 15–20 cm tall and often already sets the first bud. Harden it off for a week or two before planting: take it outside during the day and back in at night.

Greenhouse and polytunnel: from mid-May, once the temperature inside does not fall below 10–12 °C at night.
Outdoor bed: only at the beginning of June, in the warmest spot in the garden. Black mulching film, which warms the soil by several degrees, or horticultural fleece overnight helps.
Container: at least 15 l per plant, better 20 l, with drainage holes. Aubergine in a container thrives on a south-facing balcony, where it is warmer than in a bed.

The spacing is 50 cm in the row and 60 cm between rows. Add a handful of well-rotted compost to the hole, plant the seedling at the same depth at which it grew in the pot and tie it straight to a cane. The fruits are heavy and the stem snaps without support. How to choose a greenhouse or polytunnel is described in the article Greenhouses, polytunnels and cold frames.

Care during summer: watering, feeding and training

Watering

Aubergine wants even moisture. Water at the roots, not on the leaves, in the heat of a greenhouse even daily. Fluctuation between dryness and overwatering leads to flower drop and bitter fruits. A mulch of straw or cut grass holds moisture and at the same time cools the surface on hot days.

Feeding

Until the first fruits are set, the nutrients from compost are enough. After that feed every 2 weeks with a fertiliser with a higher potassium content, for example Hoštické fertiliser for tomatoes and peppers, which also suits aubergine. Too much nitrogen means lush leaves and few fruits.

Training and number of fruits

When the plant is 30–40 cm tall, pinch out the tip so that it branches. Leave the 3–4 strongest shoots. With large-fruited varieties leave 5–6 fruits on the plant, with small-fruited ones even 10–15. Pinch off further flowers and small fruits, otherwise no fruit will grow properly. At the end of August remove all new flowers, as they would not ripen before winter.

Pollination

Aubergine is self-pollinating, but in a closed greenhouse without insects it helps to shake the plant gently on a sunny morning. An open ventilation window and flowering herbs nearby attract bumblebees.

Harvest: when an aubergine is ripe

Aubergine is harvested at culinary ripeness, before the seeds are fully ripe. You can tell it by three signs:

the skin is glossy and has the typical colour of the variety,
when pressed with a finger the dent evens out at once,
the fruit has reached the size stated for the variety.

When the skin goes dull and the seeds inside turn brown, the fruit is overripe, and the flesh toughens and becomes bitter. Cut the fruits off with a knife or shears together with the stalk and calyx, taking care of the small spines on the calyx. In the fridge they keep for about a week; cold below 8 °C harms them.

Only the fruits are edible. The leaves and stems of nightshade plants contain glycoalkaloids and are not eaten. Aubergine goes on the plate cooked: grilled, roasted, stewed or baked.

Why aubergine does not grow or fruit

Symptom	Most common cause	What to do
seeds do not germinate	cold compost below 20 °C	heated mat, lid, patience of up to 3 weeks
spindly, weak seedlings	too little light and too much warmth	south-facing window or lamp, night temperature 16–18 °C
stops after planting out	cold soil and nights below 12 °C	later planting, film, fleece at night
flowers drop	cold, heat above 32 °C, drought	ventilate, shade, water evenly
fine webs, spotted leaves	spider mites in a dry greenhouse	raise air humidity, mist, in need predatory mites
chewed leaves, orange larvae	Colorado beetle	regularly collect beetles and larvae

Aubergine also suffers from aphids and whitefly, similarly to peppers. The approach against them is the same as in the article What can befall peppers. Do not plant it after tomatoes, peppers or potatoes, so that nightshade diseases do not build up in the soil.

Frequently asked questions

When should I sow aubergine?

From mid-February to mid-March on a windowsill or in a heated propagator. For growing in a greenhouse you can start as early as the end of January, for an outdoor bed the beginning of March is enough.

How long does aubergine take to germinate?

At 25 °C in 7–14 days. Below 21 °C it germinates slowly and unevenly, sometimes taking up to 3 weeks. If nothing has come up even after 3 weeks in warmth, the seeds will not come up.

Can aubergine be grown outdoors?

Yes, but only in the warmest spot, planted out at the beginning of June and ideally with mulching film. The yield is smaller than in a greenhouse. A container on a south-facing balcony or by a wall is more reliable.

How many fruits does one plant give?

With large-fruited varieties 5–6 fruits of 300–500 g, with small-fruited and cylindrical ones 10–15 smaller fruits. The plant cannot nourish more fruits in our short summer.

Why is my aubergine bitter?

Most often it is overripe, with a dull skin and brown seeds. Bitterness is also increased by drought and heat stress. Harvest earlier, while the skin is glossy.

How big a pot does aubergine need?

At least 15 litres, ideally 20 litres per plant. In a smaller container it dries out quickly and drops its flowers.

Sources

Updated: 27 September 2026

Author: Jana Vránová, the editorial name of the Pěstík.cz team. She writes about the garden, herbs and essential oils. We take safety and dosage data from specialist literature and official sources, which we cite in every article.