Ethiopian Eggplant

About

The Ethiopian eggplant is an aubergine that has decided to look like a tomato. The fruit ripens through cream and green to a bright scarlet or orange, ribbed and glossy, 3 to 8 cm across, and anyone meeting one for the first time usually assumes it is a tomato until they cut it.

It is one of the most widely grown vegetables in Africa and it comes in groups selected for different jobs. The Gilo group is grown for its fruit and dominates in West Africa and Brazil. The Shum group is grown for its leaves, eaten as nakati in Uganda, and its fruit is small and barely worth picking. The Kumba and Aculeatum groups sit between the two.

Bitterness is part of the design. The fruit carries more glycoalkaloid than a common aubergine and tastes noticeably bitter, which is what it is grown for in the stews it goes into. Cooks pick the group and the stage to suit the dish rather than trying to breed the bitterness out.

Appearance and character

A bushy branching plant, 60 cm to 1.5 m depending on the cultivar group, woody at the base by the end of the season.

Stems are green or purple-flushed, sometimes carrying short prickles, and the prickly forms are the ones to handle with care.

Leaves are broad and ovate with shallow lobes, 10 to 25 cm long, softly hairy, larger and thinner than a common aubergine’s.

Flowers are typical Solanum, 2 to 3 cm across, white to pale violet with a protruding cone of yellow anthers, in small clusters.

Fruit changes colour as it goes. Young fruit is white, cream or green, often striped; it ripens through orange to a strong scarlet red, and it is usually eaten at the pale or green stage rather than red.

Shape runs from a flattened ribbed tomato to a small round ball to a slim egg, 3 to 8 cm across.

Cut open, the flesh is white to greenish with numerous small flat seeds, and it firms and darkens with age.

The leaf-type cultivars look quite different, being lower, broader-leaved and grown as a cut-and-come-again green.

Where it is from

Solanum aethiopicum was domesticated in West and Central Africa from the wild Solanum anguivi, and it is one of the small number of vegetables that are entirely African in origin despite the Ethiopian name.

Cultivation spread across the continent, and it is now among the most important vegetables in Nigeria, Uganda, Cameroon, Ghana and the Democratic Republic of the Congo, grown both for fruit and for leaves.

Portuguese trade carried it to Brazil, where it became jilo and is a standard market vegetable in Minas Gerais and Rio de Janeiro, cooked with beef or fried in slices.

Southern Italy grows a small amount as a curiosity crop, and it turns up in Caribbean gardens.

It turns up in African and Caribbean grocers across Europe and North America, usually as small scarlet or striped fruit sold loose, and seed is now easy to buy from specialist suppliers.

How it grows

Sow in March or April at 22 to 25 deg C, as you would an aubergine, in modules or small pots.

Germination takes one to three weeks and is unreliable below 20 deg C.

Prick out into 9 cm pots and grow on warm and bright.

Plant out into a greenhouse or polytunnel border in late May or June, 45 to 60 cm apart, once nights hold above 12 deg C.

Give full sun and warmth. It is more tolerant of cool nights than a common aubergine but it still wants heat.

Pinch the growing tip at about 30 cm to make the plant branch, which increases the number of fruit.

Stake taller cultivars, since a plant carrying a heavy crop leans.

Water and feed steadily from the first flower.

Harvest fruit young, at the pale or green stage for most cultivars, when the skin is glossy and the flesh still firm.

Pick leaves as a cut-and-come-again crop from the leaf-type cultivars, taking the young growth from the tips.

Through the seasons

March and April are for sowing warm, on a propagator.

May is growing the young plants on somewhere bright and frost free.

June is planting out under cover.

July is branching growth and the first flowers, and the point to pinch the tips.

August is the main fruiting month, and the leaves are at their best for picking too.

September carries on, with fruit colouring up if left on the plant.

October ends it as the light fails.

Winter does not apply, though a plant kept warm and bright will survive to a second year and crop earlier.

Care difficulty

Moderate, and easier than a common aubergine under glass.

Germination needs 22 deg C and a little patience.

The plant is more tolerant of cool nights and less prone to sulking than Solanum melongena.

Red spider mite and whitefly are the two pests that decide how long the crop lasts.

Picking at the right stage takes learning, since the fruit changes fast.

Grown as a leaf crop it is easier still, and it crops from July to October.

Watering

Water twice a week from planting out.

Increase once fruit is setting, since irregular watering makes the fruit bitter and seedy.

Keep the plant evenly moist rather than swinging between dry and soaked.

Water at the root in the morning.

Mulch to hold moisture.

Reduce in October as the plant slows.

Warning signs, diseases and pests

Fine pale stippling with webbing under the leaves is red spider mite, and it is the main reason a greenhouse crop finishes early.

Clouds of small white insects rising from the plant are whitefly.

Curled tips with sticky residue are aphids.

Flower buds dropping without setting means cold nights or dry roots.

Fruit turning red on the plant is ripe rather than spoiled, though it will be seedier and more bitter than at the pale stage.

Grey fuzzy mould on a damaged fruit is botrytis in still humid air.

A plant that wilts in the middle of the day and does not recover, with brown staining in a cut stem, is verticillium wilt, and the border needs a rest from solanums.

Bitterness far beyond the usual usually follows a drought.

Growing environment

A greenhouse or polytunnel where summers are cool. Outdoors is possible in a hot summer against a wall.

Full sun.

Minimum 12 deg C, with 22 to 30 deg C for growth.

Rich free-draining soil with compost dug in.

Spacing of 45 to 60 cm.

A stake for the taller fruiting cultivars.

Good ventilation, which keeps red spider mite and botrytis down.

Feeding

Dig in garden compost before planting.

Feed a balanced liquid feed fortnightly from planting out.

Switch to a high-potash tomato feed once the first fruit sets.

Feed weekly through the main cropping period.

Feed the leaf-type cultivars a balanced feed throughout instead, since leaf is the crop.

Stop feeding at the end of September.

Troubleshooting

Is this a tomato or an aubergine? An aubergine. Solanum aethiopicum is in the same genus as the common aubergine and looks like a tomato by coincidence rather than by relationship.

Why is it bitter? Because it is meant to be. The fruit carries more glycoalkaloid than a common aubergine and the bitterness is what African and Brazilian cooks want in the dishes it goes into.

When should I pick it? For most cultivars, at the pale cream or green stage when the skin is glossy and the flesh firm. Left to redden it grows seedier and more bitter.

Can I eat the leaves? Yes, cooked. The Shum group is grown specifically for them and they are a staple green in Uganda under the name nakati. Take the young growth from the tips.

Do I need to salt it like an aubergine? Not usually. Salting draws out some bitterness if a particular fruit is stronger than you want.

Can I grow it outdoors in a cool climate? Against a hot wall in a mild district, in a good summer, you may get a crop. Under cover is far more reliable.

What is jilo? The Brazilian name for the Gilo group, sold in every market in Minas Gerais and fried in slices.

Is it prickly? Some cultivar groups are, particularly the Aculeatum group. Check the description before you buy seed if that matters to you.

My plant wilted and will not recover. Cut a stem and look for brown staining in the tissue. Verticillium wilt is common where tomatoes and aubergines have grown in the same border for years, and the answer is a fresh site or fresh compost.