Whatever you do to avoid it; sooner or later there is a plant with rot. We recently experienced this with a quiver tree which prosphered in one of the gardens for more than 6 years. And suddenly, at the brink of the South African Autumn, the tree let us know that there was such a ‘soft feeling’ at its neck. Taking the soil away we discovered that part of the neck just started to rot. We took it out (almost 150 kilogram) and laid it to rest in the barn. The past week we’ve taken the rot parts away and let dry for the next few months until Spring before we replant it. Luckely for both, us and the tree, some of the roots were not attached. In October we will replant the almost 3 metre high tree on a somewhat higher spot and we’ll cover the neck and the top part of the roots with coarse sand for better drainage.
Rot can never be avoided in full but some measurements can avoid at least 90 percent of the misery.
It starts with buying your succulents.
And plant them in the right soil; more or less the mix as described in one of the contributions last month.
The top layer of the soil should be 30 to 50 cm deep and the subsoil should be able to drain the surplus of water sufficiently even after a heavy rainfall.
Keep the soil around the plants free of weeds.
Plant vunerable succulents on a small sandy heep (5-10 cm high).
After (heavy) rainfall aerate the soil around the plant (loosening the top few centimetres).
But still than, as in our case with a very valuable quiver tree, rot can strike suddenly.
Neck-rot is caused by phytophthora. This is a fungus which also occurs in potatoes and caused the Irish famines in the 19th century and with that the Irish influx in the America’s.
There is not much what you can do in a natural way other than taking the affected plant out and cut the rot part out. If you discover the disease in a late stage it can be too late for the whole plant. The only thing left is to cut the plant off above the neck and let the stem dry first and than root again as a cutting.
ALWAYS remove the soil around the affected plant (it might be contaminated) and do not add the attached parts (or whole plants) to the compost heep for it will spread the disease to all the places where you spread the compost.
Connie Krochmal, the cactus and succulent editor of Bella Online, recently wrote an informative article about all kinds of (rot-related) diseases in cacti and other succulents such as fusarium, botrytus and (powdery) mildew.
At last but not at least: communicate with your plants. They will tell you about their needs, their shortcomings, their symptoms of ‘illness’. Talk with them with your eyes, your fingers, you nose and also with your mouth. It helps. Really.