When to plant aubergines?

When, by region

March–April indoors and May–June at 16-25 °C, with the stop below 10-12 °C, are from Valle d'Aosta's Informatore Agricolo. A minimum of 21 °C to germinate, January only in a heated greenhouse, and planting out in late May or early June, are from the RHS. The 8-10 days at 20-25 °C, nights at 15-16 °C and days at 23-25 °C in the open ground, and protected transplanting from February to October, are from Campania. Peppers have a different window: when to plant peppers. The months are in the March calendar, May and June.

Later than tomatoes

In Valle d'Aosta the seedbed is March–April, not February. The seed wants at least 21 °C (70 °F): the RHS says so, and Campania asks for 8-10 days at not less than 20-25 °C. As soon as it shows, move it into the light, at 16-18 °C (60-64 °F). With the first true leaves, a 7.5 cm (3 in) pot.

For outdoor plants the RHS sows in early March, not before: the plant stays inside until frost has passed, and a January sowing leaves it in a pot for months. January makes sense only if the greenhouse is heated. The method is in starting seeds indoors. Tomatoes, which start earlier, are in when to plant them.

Planting out, and pots

Valle d'Aosta transplants in May and June, root ball intact, rows 60-80 cm apart and plants 50 cm apart. The crop runs 150-180 days. The RHS, outdoors, plants in late May or early June, 60 cm (2 ft) apart, after a couple of weeks of hardening off, and covers them for a couple of weeks. An unheated greenhouse moves that to early May; a heated one, to April.

In Campania, single rows are 80-120 cm apart, plants 40-60 cm apart. In the open ground, with standard cultivars, 2.5-3 plants per square metre. In Sicily the maximum density, under cover and in the open ground, does not go above 2-2.5 plants per square metre. In a pot, one at least 30 cm (1 ft) wide, one plant; in a growing bag the RHS sets two. It does well in a pot: Valle d'Aosta says so too. See the container garden.

Once the plant is about 30 cm tall, the RHS pinches the main stem so side shoots grow. On large-fruited varieties, once five or six fruits have set, it removes later flowers. From sowing to harvest, count at least five months.

Water, and where not to return

They want steady water. In a pot, in summer, that can mean every day. In Campania, growth is happiest at 18 °C at night and 25 °C by day. Water the soil: how much is in watering.

In Umbria, in the open ground, it is a renewal crop: cereals or legumes can follow. Under cover, without a resistant rootstock, wait at least three years before repeating aubergines and before other solanums or cucurbits. The longer gap, the late-blight one for tomatoes, potatoes, peppers and aubergines, is in late blight, and the plan is in crop rotation.