Humankind has always had a morbid fascination with danger, and this often translates into the garden.
A perfect example is Adenium boehmianum, the bushman poison plant.
The people in its native region of southern Angola and northern Namibia use this plant’s sap as a hunting poison.
Despite a short bloom time and the plant’s being stuck between deciduous (leaves fall off for winter) or evergreen, bushman’s poison has a small but devoted fanbase as an ornamental plant.
These perennial succulent plants are members of the Apocynaceae family and one of the many victims of the Great Adenium Debate.
It is often considered by some experts to be its own species of adenium, while others want it classified as Adenium obesum subsp. Boehmianum.
The indecisiveness also carries over into its common names. It is usually called bushman poison (or bushman’s poison) and bushmen’s arrow poison. Some circles insist on also calling it desert rose Adenium obesum’s common name.
It is sometimes confused with a similar adenium with narrower leaves, similar flowers, and a much larger caudex (up to 3′ feet across).
This tropical plant was formerly known as Adenium swazicum. Then it was reclassified (again, in some circles) as Adenium boehmianum var. swazicum.
Adenium obesum subsp. Boehmianum Care
Size and Growth
Bushman’s poison resembles a short tree that can reach 8′ feet tall and 2′ feet across.
The caudex tends to disappear with age, although there are tricks to keep it rounded during repotting.
Bushman poison stores most of its water in the roots, leading to fat roots and thin stems.
The plant has the largest leaves of all adeniums, measuring up to 6″ inches long with a broad, club shape.
The glossy greyish green foliage only lasts for about 3 months and groups in spirals around the end of each branch.
This slow-growing plant with long periods of dormancy tends to be most active towards winter (which is summer in its native habitat).
Flowering and Fragrance
Bushman’s poison tends to only bloom for a few weeks in the winter.
The 2″ inch flowers are trumpet-shaped and have more variance than many other adeniums.
The color can range from pale pink to deep magenta, white, or even crimson red with a dark purple throat.
These flowers give way to oblong fruits, which spill their seeds out through a vertical slit, allowing them to disperse into the wind.
Light and Temperature
This plant likes full sun in more northern climates but the caudex needs protection with smaller plants to prevent burns.
Conversely, bright, indirect light or lightly dappled shade can protect the plant without denying it enough light.
More arid environments are preferable, as high humidity can lead to rot.
USDA hardiness zones 10a to 11b are best for this plant, although they often do well in zone 9b.
The plant is not cold-hardy and can suffer permanent damage when exposed to 59° degrees Fahrenheit or below.
Indoors, aim for a temperature of around 77° degrees Fahrenheit.
Water and Fertilizer
Proper watering is perhaps the trickiest aspect of owning a bushman’s poison arrow plant.
Avoid underwatering, as this may cause the plant to go into its dormant rest period early.
Overwatering will cause root rot, and this plant can quickly die from the condition.
Wait until the soil is dry at least a few inches down and use the soak and dry method (saturate the soil, then let it become dry partway down again).
Or follow a more general guideline for outdoor plants, such as watering twice per month in spring and summer and once per month the rest of the year.
A healthy plant will need a fertilizer rich in phosphorus and potassium but low in nitrogen.
Dilute a liquid cactus or succulent fertilizer meeting this ratio by following the instructions on the package. Apply it once per month during the spring and summer.
Related: Fertilizer For The Desert Rose
Well-Drained Soil and Transplanting
Adenium boehmianum can be a finicky plant when it comes to soil due to its adaptation to growing in rocky areas.
For potted plants, you will need a container with plenty of drainage holes.
A substrate of a few porous materials (charcoal pieces, coarse sand, perlite, pumice, small stones, and vulcanite) is essential. Use in the garden or a pot.
As with many other adeniums, this species uses the top third of its well-drained soil more for support or composting than actual food.
More on the Desert Rose Potting Mix
You may choose to fill this top third with a succulent potting mix, as water will slowly filter some of the soil down into the substrata.
Repotting is an infrequent need with this species. You will know it’s time when you see the roots beginning to poke out of the drainage holes.
Do you’re repotting in the summer and upgrade the container by one size.
You can keep the caudex swollen by raising the plant slightly each time you transplant.
Grooming And Maintenance
The following tasks are not necessary, but will help keep your plant healthy and attractive:
- Removing suckers
- Trimming damaged leaves
How To Propagate Bushman Poison Plant
Propagate this plant with seeds if you want a swollen caudex.
However, cuttings and grafting are also viable methods.
Bushman’s Poison Arrow Pests or Diseases
This plant doesn’t have a lot of issues, but fungi and root rot are significant threats.
Additionally, aphids and spider mites seem to love the bushman poison plant.
As the name implies, this plant is toxic, and the sap is used for hunting large animals.
Always wear gloves when handling and keep away from children and pets.
Adenium Boehmianum Uses
This plant is an excellent addition to rock gardens or indoor ornamentals when kept away from kids and pets.