Scientific Name — Trichodiadema bulbosum

Common Name(s) — African Bonsai or Miniature Desert Rose

Plant Family — Aizoaceae

Background

This South African native is true to its bonsai nickname with a distinct, trunk-like caudex and many leafy branches. The wiry, dense branches of this plant will form a low shrub structure and blossom with brilliant pink-petaled flowers during a long growing period from spring to autumn. 

The root foot, or caudex, of Trichodiadema bulbosum is typically allowed to develop for several years before it is repotted with the caudex partially exposed above the soil. This doesn’t harm mature plants, and gives the specimen a particularly architectural look.

Traditionally, the roots of Trichodiadema species have been used to speed the fermentation of bread and beer. They are said to contain either yeast or sugars that boost fermentation processes.

Growth Requirements

Sun

African Bonsai does best in filtered sun, 4 to 5 hours a day. Avoid intense afternoon sun by sheltering this plant beneath the limbs of a larger plant or placing it in the shadow of a sheer curtain.

Grow outdoors in light shade or indoors in a sunny window with southern exposure.

Temperature/ Humidity 

Trichodiadema bulbosum prefers warm temperatures in the 70s and 80s. It can become stressed if left in conditions of extreme temperatures or intense sun.

These plants are not cold-hardy. If grown outdoors, migrate these plants to a sunny spot indoors when nighttime temperatures drop below 55 ºF.

Water

Native to arid and sub-tropical climates, Trichodiadema bulbosum is a drought-tolerant plant. Water when the soil dries out in the summer and only infrequently during the winter. Its soil should be allowed to dry out entirely before watering thoroughly.

When the plant is actively flowering, give it a little more water. When flowers fall off, dial back on water.

Soil/Roots

These plants prefer a sandy, sharply draining mix. Cacti or succulent potting mix is great. You can amend a regular potting soil with sand or pumice up to 50% to improve grittiness and drainage.

Flowering

Trichodiadema bulbosum produces pink flowers with yellow centers most often during the spring and summertime. Flowering may continue into autumn if conditions are optimum.

Fertilization

These plants do not require fertilizer, though it can be added to give container-grown plants a boost or to supplement poor soil. Apply a water-soluble, balanced fertilizer monthly, diluted at half strength. 

Propagation

Trichodiadema bulbosum can be propagated from stem cuttings. The best time to do this is late spring or early summer.

• Allow cuttings to callous for one to two weeks

• Dust with rooting hormone

• Place in soil

Health

Diseases and Pests

Trichodiadema bulbosum is not prone to pests.

Though not super common, they are more likely to fall victim to bacterial or fungal infections. Affected plants may need to be destroyed to prevent the spread of disease to other nearby plants.

Maintenance (pruning, legginess, repotting)

Little maintenance is required to grow these plants.

This plant loves to be rootbound in a pot. Once planted, they will be happy in the same pot for several years. Repot once every two to three years.

If you have a young Trichodiadema bulbosum, do not plan on exposing the caudex until it’s fully established.

Toxicity 

Trichodiadema bulbosum is not toxic to humans or pets, but should not be ingested.

FAQs

What’s the best temperature range for my Trichodiadema bulbosum?

This is a plant that prefers a climate that is neither too hot nor too cold. The ideal range is between 70-85 °F.

Both intense heat/sun and cold temperatures can stress the plant, so keeping them outdoors in very hot summers or winters that regularly see temperatures below 55 °F is not advised.

Why isn’t my African Bonsai flowering?

Although filtered light is preferred, if your Trichodiadema bulbosum doesn’t get enough light, it may not flower. Also, be careful not to overwater.

Why must I protect the caudex on a young Trichodiadema bulbosum?

While the caudex is often exposed on mature plants, when an African Bonsai is younger, it hasn’t developed a strong, healthy caudex. Wait until the plant has fully matured, and then gradually expose the caudex.