Lobelia erinus (edging lobelia)

Japanese name: ロベリア
Scientific name: Lobelia erinus

[Overview]
A perennial 10–25 cm tall.
It dislikes heat and humidity, so in Japan it is usually treated as an annual sown in autumn.
The stems are slender and branch well, and some types creep along the ground.
The leaves are simple and alternate, linear to elliptic, about 1–1.5 cm long, with serrated margins.
Racemes bear two-lipped flowers about 1.3–1.8 cm across.
In the corolla the upper lip is small and 2-lobed, and the lower lip is large and 3-lobed; some plants have white or cream-colored blotches in the throat.
The fruit is a capsule.

[Cultivation]
Propagate from seed.
It prefers a sunny, well-ventilated, fertile and moist environment, and dislikes dryness.
Avoid the strong afternoon sun of midsummer.
To keep it through the summer, grow it in a pot and move it to airy partial shade in midsummer.
For potted plants, when the soil surface dries, water thoroughly until water runs out of the bottom of the pot.
For plants in the ground, established plants tolerate dryness, but water if the soil is dry.
If it is not to be kept through the summer, a base fertilizer of slow-release fertilizer is enough; if it is to be kept through the summer, also place fertilizer on the soil in spring and autumn.
Cutting it back before the rainy season makes it easier to keep through the summer.
Pests include spider mites and aphids.

View this page in Japanese (日本語)