Solanum aethiopicum (bitter tomato, "Hananasu")

Japanese name: ハナナス （花茄子）
Scientific name: Solanum aethiopicum

[Overview]
A perennial or subshrub about 1 m tall, but because it is sensitive to cold and frost, it is treated as an annual.
Stellate hairs cover the whole plant, and the stems and branches have spines.
The leaves are simple and alternate, ovate to oblong, 10–20 cm long and 6–14 cm wide, often with spines on the veins.
The leaf margin has low, large teeth or is wavy-lobed.
Several flowers are borne in racemes arising from midway along the stem; the corolla is 1.5–2.5 cm across, white or slightly purplish, star-shaped, and 5-lobed (6–9-lobed).
The fruit is oblate, 3–5 cm across, with several vertical grooves, and ripens orange or red.

[Uses]
In Japan it is grown as an ornamental, but in some regions the fruit is used medicinally or eaten.
It is also used as a rootstock for Nasu (eggplant).

[Cultivation]
Propagate from seed.
The optimum germination temperature is high, 20–25°C, and since the fruit takes time to color after setting, late sowing may cause the plants to die before the fruit colors.
It prefers sunny, well-ventilated, fertile soil that is well drained and retains moisture.
Grow it in a large pot of No. 10 or larger, or in a large planter.
For potted plants, water thoroughly when the soil surface dries; for plants in the ground, rainfall is sufficient unless sunny weather continues and the soil dries out.
Apply slow-release fertilizer during the growing season until the fruit ripens.
Fertilizer high in nitrogen produces only leaves and makes flowering difficult, so use a fertilizer with equal amounts of the three components or one lower in nitrogen.
Pinch in early summer, and when side shoots grow, leave only a few and cut off the rest to control the number of fruits per plant.
Once fruit has set, removing leaves that shade the fruit lets in more sun and gives good color.
The plant grows tall, so provide stakes.
Pests and diseases include powdery mildew, aphids, armyworms and spider mites.

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