| Annual or perennial | Annual (tropical perennial grown as annual) |
| Difficulty | Moderate to challenging in cooler climates |
| Height | 60-100cm |
| Spacing | 50-60cm |
| Harvest window | August to October |
Aubergine is the most heat-demanding of the classic summer vegetables. In Alsace it is possible but benefits greatly from a warm spot, a sheltered wall, or container growing. Homegrown aubergines have a creamy, nutty flesh that shop varieties rarely approach.
Which variety to grow
Choose compact, early-maturing varieties. ‘Monarca’, ‘Bonica’, and ‘Orient Express’ perform well in cooler climates. Long, slender Japanese varieties ripen faster than large round types. Avoid large Italian varieties unless you have a greenhouse.
When to plant
Start seeds indoors in February at 24-26 degrees (a heat mat is almost essential). Plant outside after all frost risk has gone – mid-June in Alsace. A greenhouse or polytunnel is the most reliable option.
How many to grow
Two to four plants to start. Each plant typically produces 4-8 fruits in a good Alsace summer outdoors. Start small and see how your site performs.
Conditions it needs
- Sunlight: Full sun in the hottest, most sheltered spot you have.
- Soil pH: 5.5-6.5
- Soil type: Rich, moisture-retentive, well-draining.
- Heat: Below 15 degrees at night and growth stalls completely.
Container growing
Containers are a very good option in Alsace. Use large pots (at least 20-30 litres) and place against a south-facing wall. The thermal mass significantly improves performance. The ability to move pots if weather turns cold is a real advantage.
How to care for it
Water consistently and generously in hot weather. Feed weekly with high-potash tomato fertiliser once flowering begins. Pinch out the growing tip when the plant has 5-6 side branches. Remove excess fruits – 4-6 per plant gives better quality than leaving too many.
Propagation
Grown from seed each year. Seeds need warmth to germinate (24-26 degrees). Save seeds from fully ripe, over-ripe fruits of open-pollinated varieties.
Watch out
Red spider mite thrives on aubergines in hot, dry conditions. Look for fine webbing and mottled leaves on undersides. Mist the leaves regularly and maintain humidity to prevent it. Once established it spreads fast.
Companion planting
Marigolds are the best companions – deter whitefly and spider mites. Basil and thyme are good nearby.
Problems to watch for
- Red spider mite: Fine webbing in hot dry conditions. Mist regularly to prevent.
- Aphids: On growing tips. Remove by hand or blast with water.
- Verticillium wilt: Yellowing and wilting. No cure – remove plant.
When and how to harvest
Harvest when fruit is full size and skin is smooth, taut, and shiny. A dull skin means it is past its best – the flesh will be bitter. Use secateurs to cut the stem. Harvest frequently to encourage more fruit.
How to store
- Fresh: Do not refrigerate – cold turns aubergine bitter. Use within 3-4 days at room temperature.
- Roasted and frozen: Roast, peel, and freeze in portions for winter use.
In the kitchen
Savory
Ratatouille, baba ganoush, melanzane alla parmigiana, caponata, miso aubergine, stuffed aubergine, imam bayildi (Turkish braised aubergine), moussaka with lentils or chickpeas. Salt the flesh before cooking (slice, salt, leave 30 minutes, rinse) to reduce bitterness and improve texture.
Sweet
Aubergine jam is a Middle Eastern specialty. Chocolate and aubergine cake uses the vegetable’s density to create a wonderfully moist texture.
Drinks
Not typically used in drinks, though smoked aubergine adds depth to gazpacho-style blended cold soups.