Euphorbia ingens E.Mey. ex Boiss.

Distributed throughout Southern Africa, Euphorbia ingens is one of the largest of the tree euphorbias reaching up to 10 meters tall in habitat. The main stem branches and rebranches to form a broadly cone-shaped crown of straight, erect, or ascending subparallel branches. Interestingly, older branches do not tend to fall off, which results in a dense and compact tree-like structure.

The main stem consists of four sides, slightly concave and edged with spines that are non-continuous and grey on older growth with the newer spines appearing rusty in colour. These spines are about 0.3–0.5cm in length. They are in pairs, and each set of spines is derived from an appendage (stipule) found at the base of the leaves. The leaves are fairly insignificant as are the flowers, which are about 0.5cm in length and width. The clustering  pale green flowers are easy to miss.

I acquired my plant about three years ago as a 3ft (0.91m) tall green ‘pole’ (Fig. 1) in a pot (my husband’s description!). Initially, it lived indoors but as my collection increased it found its way outside to my unheated greenhouse where it has lived quite happily for the past two years – even surviving the extremely cold temperatures of December 2022!

I was delighted when in July 2023, the plant began to form branches (Figs. 2 & 3) and is finally starting to resemble one of its common names, the ‘Candelabra Tree’. I have only re-potted the plant once, about two years ago, and I was surprised at the relatively small size of the root ball. Despite this, I re-potted it into a larger container, mainly because I was worried it would topple over if it got much taller!  I used a mix of half peat-free John Innes No. 2 and half of sharp sand and grit mix. It seems happy in this so far, though I am a cautious waterer and I do keep it completely dry over the winter. I use a regular cactus fertiliser through the summer with every 2nd/3rd watering.

I have no idea what I will do when the new branches start to grow much longer, as I am not sure I will be able to get it out of the greenhouse door, but I can worry about that as and when it happens.