They open in late afternoon but may open earlier on dark or overcast days. Seeds must be soaked or otherwise scarified before planting. These perennials thrive in full sun, in any moderately fertile soil. Four o'clocks bloom in late afternoon. Its yellow blooms open in the evening.
Plants require full sun.
The genus Nicotiana, or tobacco, includes ornamental species such as N. alata and N. sylvestris as well as various hybrids. The ornamental varieties are annuals or short-lived perennials grown as annuals. Contact with foliage may irritate skin. All parts of angels' trumpets are poisonous if ingested, so plants must be kept out of the reach of children and pets. Grow in full sun, and prune in early spring.