Succulent Bush Senecio

About

Succulent bush senecio is an upright shrubby succulent with woody stems and slim, finger-like, cylindrical green leaves that stand out all around. A mature plant forms a dense, rounded bush a metre or two high, covered in fleshy green leaves. In winter it carries clusters of small, bright yellow, sweetly scented flowers, which is where its other name, lemon bean bush, comes from.

It is a drought-hardy shrub of the dry southern African bushveld, at home in strong, unbroken sun, stony ground and long rainless spells. Fast-growing and easy, it makes a strong structural succulent for a sunny sill, a conservatory or, in a frost-free climate, a garden, and it takes hard pruning to keep it shapely.

It belongs to the senecios, the same group as the trailing string of pearls and string of tears, and shares their mildly toxic, irritant sap, so it is one to keep from chewing pets. Grow it sunny, lean and dry, and it usually flowers in winter.

Appearance and character

The leaves are slim, cylindrical and finger-like, a fresh green, standing out all around the woody stems, so the plant looks like a dense, bristling bush of soft green fingers.

The stems are upright and branching, turning woody with age, and build into a rounded shrub one to two metres tall, faster and more shrubby than most succulents.

It takes hard pruning well, which keeps it dense and shapely and provides cuttings, and it roots readily from those cuttings.

Its flowers are clusters of small, bright yellow, sweetly scented blooms at the shoot tips in winter, a welcome show when little else is out.

Where it is from

Senecio barbertonicus grows in the dry bushveld and rocky slopes of southern Africa, in strong sun and low rainfall, storing water in its finger-like leaves against drought. It is a plant of heat and aridity.

Those origins govern its needs. It thrives on strong, direct sunshine, compost that empties fast and long stretches without water. It tolerates heat and drought, while a cold, wet root run is the one thing that rots it. Its irritant, mildly toxic sap is the senecio family trait, and the reason to keep it from pets that chew.

How it grows

It grows fast for a succulent through the warm months, branching and bushing out, flowers in winter, and slows in the coldest, darkest weeks. Full sun keeps it dense and firm; poor light makes it leggy and sparse.

Pot it in a very open, gritty succulent compost in a container to match its size, and water only once that compost has dried right out. The finger-like leaves hold their own reserve, so it needs watering only now and then, though its quick pace means it drinks a little more than a slow succulent in summer.

Give it full sun, warmth above about 3 deg C, and dry conditions, and prune it back in spring to keep it bushy. Move a plant that has summered outdoors back in before frost.

Propagation is very easy. Stem cuttings, dried for a day or two, root readily in gritty mix.

Through the seasons

Spring sets off rapid growth as the light and warmth build. Prune to shape, begin watering again, and take cuttings.

Summer carries the bulk of the growth. Give water once the compost has dried out, add a little dilute feed, and hold it in full sun.

Autumn slows growth and sets the flower buds. Ease off watering.

Winter brings the scented yellow flowers. Keep it bright, cool but frost-free, and water sparingly, since cold, wet compost rots it now.

Care difficulty

Easy, fast and forgiving, given full sun and sharp drainage. It grows quickly, prunes hard, roots readily and flowers in winter with little help. Its one weakness is cold, wet compost, which rots it, so keep it dry in winter. Its mildly toxic sap is the main reason for care, calling for it to be kept from chewing pets.

Watering

Once the gritty compost has dried right out, drench it and let the surplus run away. The finger-like leaves store water, so the plant tolerates drought, though its fast growth means it takes a little more in summer than a slow succulent.

Water sparingly over winter, when cold, wet compost is the main danger, even as it flowers. Leaves that shrivel are thirsty; a soft, discoloured base points to rot from overwatering.

Warning signs, diseases and pests

Cold, wet compost rots the roots, the commonest way to lose it, shown by softening, discoloured stems at the base. Improve drainage, water sparingly, and keep it warmer and drier.

Mealybugs and aphids gather on the soft shoots and flowers and can be wiped off with dilute alcohol or treated with oil. Take care to keep the irritant sap off skin while working on it.

Leggy, sparse, stretched growth means too little light. Move it into full sun and prune it back to force dense new growth.

Growing environment

Full sun keeps the bush dense, firm and free-flowering. In poor light it grows leggy, sparse and soft. It needs as much direct light as you can give it.

Warmth above about 3 deg C and dry conditions suit it, matching its bushveld home. It needs low humidity and dislikes cold, wet, stagnant compost.

Set it in a gritty, sharply draining succulent compost in a sunny position, or outdoors in a warm, frost-free climate, and keep it clear of pets that chew.

Feeding

Feed only once or twice over spring and summer with a dilute, low-nitrogen cactus feed. It needs little, and rich feeding forces soft, leggy growth.

Give nothing over winter. Fresh gritty mix supports a newly potted or pruned plant through its first weeks.

Troubleshooting

It has grown leggy and sparse. Too little light. Move it into full sun and prune it back hard to force dense new growth, rooting the trimmings as cuttings.

The base has gone soft and discoloured. Root rot from cold, wet compost. Improve drainage, water sparingly, keep it warmer and drier, and root a healthy cutting if the base is lost.

When does it flower? In winter, with clusters of small, scented yellow blooms, which is unusual and welcome timing among houseplants.

Is it safe around pets? No. As a Senecio it has an irritant, mildly toxic sap, like its relatives the ASPCA lists as toxic to pets, so keep it from chewing animals and wash the sap off skin.

How is it different from string of pearls? This is an upright, bushy shrub with finger-like leaves, where string of pearls is a trailer with round beads. Both are senecios with a toxic sap.