Growing Senecio Plants

  • 01 of 02

    Senecio Plants

    String of Pearls Plant
    Marie Iannotti

    Senecio is a very large genus of plants, with over 1,000 species dispersed around the world. Some are lovely and others, like the groundsels and ragworts, are noxious weeds. Many, such as Dusty Miller (​Senecio cineraria), are tender perennials.

    This profile covers the succulents. There are about 100 succulent Senecios, including a few oddities that are not really suited to the garden, although they are certainly interesting. There are some large shrubs, but many are small, 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 on 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 Name

    Senecio spp.

    Common Name

    There is no common name for the whole group of Senecio plants. Each species has its own common name or names.

    Cold Hardiness

    Most fall somewhere around USDA Hardiness Zones 9 to 11. A few Senecio species can tolerate brief periods of cold or dampness, but prolonged exposure will turn them to mush.

    Sun Exposure

    Being succulents, they will grow best in full sun.

    Mature Plant Size

    Most Senecio plants 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.

    Using Senecio Plants in Your Garden Design

    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. In climates with cold winters, growing them in containers will allow you to bring them indoors, as houseplants.

    Suggested Varieties

    • Senecio crassissimus - "Vertical Leaf Senecio": Bluish, flattened leaves on an upright plant. An easy grower that can handle some frost. 18-24 inches (45-60 cm) H x 18 inches (45 cm) W. USDA Hardiness Zones 10 - 11.
    • Senecio haworthii - "Cocoon Plant": Cocoon refers to the shape of the 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. A 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.
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  • 02 of 02

    Growing and Caring for Succulent Senecio Plants

    Blue Chalk Plant
    Marie Iannotti
    • Soil: Senecio planats don't seem to be particular about soil pH. Something in the neural range (6.0 - 7.0) would be fine. More importantly, make sure the soil is on the sandy side and well-draining soil. Plants will rot if left damp.
    • Planting: Senecio plants can be grown from either seed or cuttings. Seeds require warm temperatures (55 F.) and constant moisture to germinate.

    Cuttings are easier and faster. Cut during the growing season, early spring to fall. Root in sandy soil, in containers.

    Caring for Your Senecio Plants

    Established plants are extremely drought tolerant. They do need some water, during the summer, but do not leave the soil wet for prolonged periods. Allow the soil to dry out between waterings in the winter, when they are somewhat ​dormant.

    Since they are growing in sandy soil, nutrients will need to be replenished. Fertilize annually, but lightly. Too much fertilizer will cause a lot of leggy growth.

    Taller varieties can get floppy. You can prune them back to where the stem is firm, in very early spring. You can even root the cuttings.

    Plants can be divided or repotted in early spring. If you are growing them in containers, they enjoy spending the summer outdoors. Wait until there is no danger of frost and move them back indoors in the fall.

    Pests & Problems of Senecio

    Few pests bother Senecio. They can occasionally be affected by scale and mealy bugs.