Overview and DescriptionSenecio is a very large genus with over 1000 species dispersed around the world. Some are lovely and some, like the groundsels and ragworts, are noxious weeds. Some, like Dusty Miller (Senecio cineraria), are tender perennials.
This profile covers the succulents. There are about 100 succulent Senecios. Some are oddities and not really suited to the garden, but they are certainly interesting. There are some large shrubs, but many are small, either trailing plants or spreading ground covers. As with most succulents, they are very drought and heat tolerant and not very cold tolerant.
Many Senecio species are toxic to animals. Use care and do not plant where animals or kids might be tempted to munch them.
Leaves: The leaves are thick and fleshy and can be deep green, bluish or even striped. Senecio succulent leaves vary widely in shape. Some are round, some banana-shaped, some stand upright.
Flowers: Senecio flowers form in clusters, on long stems. Different species bloom at times throughout the year. The flowers persist for weeks. Shapes include red or white spires and yellow daisy-like flowers, but it is really the foliage that interests most gardeners.
Botanical NameSenecio spp.
Common Name:There is no common name for the whole group of plants. Each species has its own common name or names.
Cold HardinessMost fall somewhere around USDA Hardiness Zones 9 - 11. A few can tolerate brief periods of cold or dampness, but prolonged exposure will turn them to mush.
Mature Size:Most are low growing, under 1 ft. (30 cm) tall. Depending on species, they may spread out or trail down about 1 ft. (20 cm).
Bloom Period:Senecio succulents are grown for their interesting shapes and leaves. They do bloom, at different times during the year, but not all of them bloom in cultivation as well as they do in the wild.
Design Suggestions:In warmer climates, you can use these plants as ground covers, rock garden plants and specimens. Most are on the small side. These are curiosities and look best in containers, either mixed or alone.
- Senecio crassissimus - "Vertical Leaf Senecio" Bluish, flattened leaves on an upright plants. Easy grower that can handle some frost. 18-24 in. (45-60 cm) H x 18 in. (45 cm) W. USDA Hardiness Zones 10 - 11.
- Senecio haworthii - "Cocoon Plant" -Cocoon refers to the shape of he gray leaves. They form a prostrate bush, but need periodic renewal. 1 ft. (30 cm) H x 3 ft. (90 cm) W. USDA Hardiness Zones 9 - 11.
- Senecio radicans - "String of Bananas" - Puffing, crescent moon-shaped leaves punctuate long stems. More tolerant of shade and moisture than most species. 6-12 in. (15-30 cm) H x 9-12 in. (22-30 cm) W. Zones 10 - 11.
- Senecio rowleyanus "String of Beads or Pearls" - Dangling stems of round leaves. Thrives on neglect. Trailing plant that gets several ft. long. Zones 8 - 10.
- Senecio serpens - "Blue Chalk Sticks", "Blue Ice Plant - Short, steel blue, tubular leaves. (Several species go by the same common names as this plant.) 12-18 in. (30-45 cm) H x 18-24 in. (45-60 cm) W. Zones 10 - 11.