Botanical Name — Monadenium rubellum
Common Name — Red Monadenium Bonsai Tree
Plant Family — Euphorbiaceae
This perennial Kenya native has a distinctive “root foot,” where it stores water during dry periods. Snake-like stems curl and flower year-round, giving this plant a unique appeal to collectors. The root foot, or caudex, is typically given many years to establish before it is repotted to be partially exposed above the soil. This doesn’t harm mature plants, and gives the specimen a particularly architectural look.
- Monadenium rubellum 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.
- Monadenium rubellum 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 night time temperatures drop below 55 ºF.
- Native to arid and sub-tropical climates, Monadenium rubellum are drought tolerant plants. Water when the soil dries out in the summer and only infrequently during the winter. Their 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.
- 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.
- Monadenium rubellum produce small purplish flowers most often during the spring and summer time, but flowers can blossom anytime conditions are optimum.
- 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.
- Monadenium rubellum can be propagated from stem cuttings. The best time to do this is late spring or early summer. Take great care when cutting these plants as they contain a sap that can be highly irritant if contacted with skin.
- Allow cuttings to callous for one to two weeks before dusting with rooting hormone and placing in soil.
- Monadenium rubellum are 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.
- Root rot can also be a concern and is triggered by overwatering. Always err on the side of underwatering.
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 Monadenium rubellum, do not plan on exposing the caudex until it’s fully established, between 8 and 12 years old.
- Monadenium rubellum is a Euphorbia. These plants contain a poisonous sap that is very toxic if ingested and highly irritant if contacted with skin. Keep out of reach of pets and children. Wear gloves and take great care when handling this plant.