[Overview]
A perennial, sometimes a subshrub, but because it dislikes heat and humidity it is treated as an annual in Japan.
The stem branches at the base and in the upper part.
The leaves are simple and alternate, linear to elliptic, with many stellate hairs and entire margins.
Corymbs or racemes emerge at the stem tips and bear fragrant 4-petaled flowers.
The fruit is a silicle.
[Cultivation]
Propagate from seed or by stem cuttings.
It prefers soil that is sunny, well drained, moisture-retentive and well aerated.
It dislikes acidic soil.
Frost damages the plant, so protection from frost is necessary.
It dislikes heat and humidity, so if you want it to survive the summer, cut it back to near the base of the plant around the rainy season.
It does better slightly on the dry side; water thoroughly once the soil has dried.
Apply slow-release chemical fertilizer as a base fertilizer, and during flowering apply diluted liquid fertilizer once every 1–2 weeks.
Pests and diseases include gray mold, sclerotinia rot and aphids.
