Growing Notes
Columnar when young, with great age this plant is treelike with a central trunk and many branches in a candelabra form. A large plant that should be given ample space to mature when planted in the garden.
Gophers and deer avoid this plant due to the toxic latex sap. It also irritates people, so avoid it and wash off skin quickly if exposed. Take extra precaution to keep the sap out of your eyes.
Nock off branches early when they are just nubs to prevent branching at a given point, if not desired. Larger branches, or even the central stem can be chopped back in early summer to lower the height of the plant. A long lived scar will remain, but new branches will start where the plant has been cut. These top sections can be rooted by allowing them to sit for two weeks in a bright warm spot and then planted in very sharp drainage. Keept warm while the cuttings are rooting. Avoid toxic sap and wash off immediately if exposed.
You may find your euphorbia develops hard brown scabs that eventually cover the cactus, especially on older growth. This is called corking, and is the natural process of the cactus ‘branch’ becoming a cactus ‘stump’ and getting bark, just like trees do. Corking is totally natural and adds to the beauty of your plant over time.
However, if the brown spots are darker and squishy, this is a sign of rot. Rot needs to be surgically removed, as it will spread and kill the plant. The sooner you catch rot, the more likely you’ll be able to save your plant. There are three possible scenarios here:
For just a little spot of rot, dig back to healthy vibrant tissue and let the plant scab and recover.
For rot that’s circled the column midway up, you’ll need to remove the top, clean the rot from both top and bottom back to healthy vibrant tissue and re-root the top. Do this by letting it scab over for 2-3 weeks and then replanting the top in very fast-draining soil (1/2 pumice or lava rock and 1/2 cactus mix) and place it in a warm bright spot out of direct sun. Rooting hormone is also useful for this, if you have it. Cement or tile floors are great for re-rooting as they transfer that heat to the plant, but you can also use a heat mat set at 72F if you have one. In this scenario you’ll get a new plant from the top, and the bottom will sprout a new head and continue growing. (This is also how you would propagate the plant, usually done in late spring when the plant is actively growing.)
If rot happens at the base, circling the column, you’ll need to propagate the top, but the bottom is done for and should be discarded. Remember when we said that the plant’s latex sap is poisonous? While doing this use gloves and DO NOT get the sap in your eyes, as it is a serious skin and eye irritant.