Euphorbia ingens, often called the candelabra cactus, gets its name ‘ingens’, meaning giant, referring to the eventual size the plant can grow to, not as you might have expected from the sharp spikes that might injure you.
In central and western Africa, from Somalia across to Angola and down to South Africa, the candelabra cactus can reach heights of 15 metres, and looks more like a tree than a cactus.
How to care for a candelabra cactus
Though not technically a true cactus, (only cacti from America are classed as true cacti) its needs as a succulent plant are just the same.
Succulents need bright, dry conditions in order to thrive. South-facing windows that get the full force of the sun are ideal, with east- and west-facing windows a close second. In a north-facing window, keeping the cactus happy will be an uphill struggle.
When it comes to watering, Euphorbia ingens has an amazing ability to hold water in its fleshy stems, and will tolerate long periods without any water at all.
In summer, when the weather is warmer, watering more frequently will encourage new growth, though still no more than once every two weeks.
In winter, you can water your candelabra occasionally, just remember that of all the things cacti hate more than anything it is wet and cold roots. If you want to err on the side of caution, you can get away with not watering from the end of October, through to the start of April, providing your plant isn’t too close to a radiator.
You’ll rarely need to repot your candelabra cactus, as they don’t have very big root systems. It’s more likely you will need to repot when your cactus becomes top-heavy, to increase the weight at the base of the plant. You can do this any time of year with a very free draining compost, or special cactus mix.
Propagating a candelabra cactus
The candelabra cactus can be propagated through stem cuttings. It’s best to start with an older plant that has started to grow side branches. Early summer is a good time to take cuttings as the plants have more warmth to grow roots and recover.
You’ll need a knife, a plant pot 10-15cm in diameter and a free-draining growing medium. You can find cactus compost in garden shops or mix your own using two parts peat-free, multi-purpose compost, one part horticultural sand and one part horticultural grit. The stem used for the cutting should be at least 20cm.
Wearing gloves, make a cut across the stem. It will bleed poisonous, milky white sap. Run the cutting under the tap until it stops and ensure the parent plant is on a surface that can be cleaned later. You’ll need to leave the cutting somewhere sunny and dry for two weeks to callus over before planting it.
This allows the wound to heal and prevent rotting. Plant it in the compost, wound side down, burying about a quarter beneath the surface. Keep it somewhere bright and water how you would the parent.