[Overview]
An annual or perennial.
The leaves are simple and opposite or whorled, and alternate and dense on the upper part of the stem.
Racemes at the stem tips bear dense flowers.
The flowers are two-lipped; the upper lip is erect and 2-lobed, and the lower lip is 3-lobed.
The base of the flower forms a long tubular spur.
The fruit is a capsule.
[Cultivation]
Propagate from seed; perennial types can also be divided.
It prefers a sunny, airy location and well-drained, well-aerated soil.
It dislikes acidic soil.
For plants set out in autumn, provide protection from the cold in winter, such as frost covers, so that they do not freeze hard.
Be careful not to overwater; plants in the ground need no special watering, and for potted plants, water thoroughly when the soil surface dries.
Apply slow-release fertilizer as a base fertilizer, and for perennial types apply additional fertilizer in spring.
If the flower stems are cut back to their base when flowering has finished, a second flush of flowers can be enjoyed.
Pests and diseases include seedling damping-off and aphids.
