[Overview]
An annual to subshrub, some reaching 60 cm in height.
It has weak cold tolerance and is treated as an annual in Japan.
The stems branch well, and many plants creep along the ground.
The leaves are simple and alternate.
Blue flowers 2–3 cm across are borne singly or several together at the stem tips and leaf axils.
The fruit is a spherical to ovoid capsule.
[Cultivation]
Propagate by division or cuttings.
It can overwinter outdoors in regions without frost, but it is safer to bring it indoors to a sunny spot in winter.
It prefers sunny, well-drained soil.
Be careful not to let it become too wet; for potted plants, water thoroughly when the soil dries, and for plants in the ground, rainfall is sufficient.
In addition to a base fertilizer, apply slow-release fertilizer once a month during the flowering period.
If the stems grow too long and become unbalanced, cut them back hard.
Pests and diseases include powdery mildew, gray mold, thrips, aphids, spider mites and leaf miners.
