Origin: The three most well-known are from Mexico
Flower color: Mostly blue, sometimes yellow and rarely white.
Flowering period: Individual flowers bloom for only for a few days, but the plant produces many flowers that bloom in succession for at least two weeks.
Average plant height: 20 inches
Planting depth to base of bulbs: 2 – 3 inches
Spacing between bulbs: 6 – 10 inches
Type of bulb: tuber, tuberous roots
Light requirements: The plants appreciate full sun, but in hot climates shaded spots are preferred during the hottest times of the day.
Application: In warm borders and in rock gardens, planters and pots.
Named after two Dutch botanists, Johann and Kaspar Commelin, who lived around 1700. Some 100 species are known and are distributed around the globe. Not all of these are tuberous; a few have tuberous roots
- Commelina coelestis (Blue spiderwort): Originally from Mexico and introduced around 1700. The plant grows to a height of 20 inches, the leaves are long and lanceolate with a width of about 2 inches and a length of 6 to 8 inches. The blue flowers appear in early summer.
- Commelina dianthifolia: Flowers later in the than Commelina coelestis: from July to August. Individual flowers bloom for only for a few days, but the plant produces many flowers that bloom in succession for at least two weeks.
- Commelina tuberosa: Introduced in 1732. Produces sky-blue flowers in June/July. Reaches a height between 15 and 18 inches.