[Overview]
An annual, biennial or short-lived perennial.
The stem is usually erect and much branched.
The leaves are alternate and simple, with entire margins or indistinct teeth.
Racemes at the stem tips bear many 4-petaled flowers.
The flower color is usually yellow, but varies widely, including red, orange and purple, and there are double-flowered cultivars.
The fruit is a silique.
[Cultivation]
Propagate from seed or by stem-tip cuttings.
It prefers a sunny, well-drained, well-ventilated site.
It dislikes heat and humidity.
Take care not to overwater; for potted plants, water thoroughly after the soil has dried, and for plants in the ground, rainfall is sufficient.
For plants in the ground, no fertilizer is particularly needed if base fertilizer has been applied; for potted plants, place slow-release fertilizer on the soil in spring and autumn.
Cutting it back to about half its height after flowering makes it easier to get through summer.
Pests and diseases include sclerotinia rot, gray mold, aphids and diamondback moths.
