Petunia ×hybrida

Japanese name: ペチュニア
Scientific name: Petunia ×hybrida

[Overview]
A perennial.
The leaves are simple, alternate and entire.
They are soft, with glandular hairs, and sticky.
At the nodes where flowers form, the leaves are opposite.
The flowers are borne singly in the leaf axils of the upper part; the corolla is salverform to funnel-shaped and shallowly 5-lobed.
There are 4 stamens and 1 staminode.
The fruit is a capsule.

[History]
Breeding centered on Petunia axillaris and P. integrifolia, which are native to South America.
From the 1980s, other wild species were also used as crossing parents, which widened the range of traits.

[Cultivation]
Propagate from seed or by stem cuttings.
The optimum temperature for germination is 25°C, and for growth 10–14°C or higher.
If sown in autumn, bring it indoors to a sunny spot in winter, or it can overwinter outdoors if protected from frost and cold wind.
Grow it in a sunny, well-drained, well-ventilated environment.
It prefers slightly acidic soil rich in organic matter.
It dislikes heat and humidity.
For potted plants, water thoroughly when the soil surface dries.
It likes fertilizer, so in addition to a base fertilizer, in spring and autumn give liquid fertilizer once every 10 days to 2 weeks, besides a top dressing of slow-release fertilizer.
Growth slows in midsummer, so withhold fertilizer then.
Pinching 2 weeks after planting makes side shoots grow and increases the number of flowers.
Crowded plants and mud splashed on the leaves cause disease, so prevent splashing with mulch and regularly tidy up spent flowers, leaves and overgrown branches.
To keep the plant from becoming stuffy in midsummer, it is good to cut it back to 1/2 its height before the rainy season.
Pests and diseases include gray mold and aphids.

View this page in Japanese (日本語)