Tagetes tenuifolia (signet marigold)

Japanese name: メキシカン マリゴールド
Scientific name: Tagetes tenuifolia

[Overview]
An annual 30 cm in both height and spread, sometimes reaching 50 cm in height.
The stems and leaves have a distinctive strong odor.
It branches freely, and the plant spreads somewhat sideways.
Leaves are alternate, about 3 cm long, finely and deeply pinnately divided, with narrow lanceolate lobes and toothed margins.
Flower heads about 1–2 cm across are borne in flat cymose clusters at the stem tips.
The flower heads of the wild species are bright yellow and consist of 5 ray florets on the periphery and 7–9 tubular florets gathered in the center.
The fruit is an achene.

[Uses]
In its native range it is used medicinally.
The flowers are used as edible flowers, served with salads and the like.
Because it is effective in controlling nematodes, it is also used as a companion plant when growing vegetables.

[Cultivation]
Propagate from seed.
If the site is sunny and well drained, it grows well regardless of soil type, but it is somewhat susceptible to summer heat, so in warm regions place it in partial shade in summer.
For potted plants, water thoroughly when the soil surface dries; for plants in the ground, rainfall is sufficient unless summer brings a long sunny spell and the soil becomes severely dry.
Too much fertilizer produces only leaves and makes flowering difficult, so unless the soil is very poor, base fertilizer alone is sufficient.
Spider mites can occur.

View this page in Japanese (日本語)