In its natural habitat, the Mediterranean oleander can be found preferably in damp places with heavy, loamy and calcareous soil. This type of soil is what the plant likes best - which, as one of the few container plants, can also tolerate waterlogging to a certain extent - which is why you should imitate the conditions found in nature as closely as possible.
Potting soil is not right for the oleander
Mix potting soil for oleanders
Many potted plants are very well cared for in commercially available potting soil, but not the oleander. This loose, humus-rich substrate is not the right soil for the flowering shrub. Instead, it is best to mix your oleander soil yourself by mixing flower soil and loamy garden soil in roughly the same ratio and, if possible, adding some sand. Don't forget to mix in a portion of long-term fertilizer with the potting soil so that the oleander gets a good basic supply for the growing season.
Repot oleanders once a year
Young oleander plants in particular grow very quickly and should therefore be repotted once a year. You change the substrate every year and choose a slightly larger pot. Older oleanders, on the other hand, only need to be repotted about every five years, and instead of putting the plant in a new container, you do a root cut. If possible, carry out this measure in the spring, immediately after clearing out the winter quarters.
tips
If your oleander flowers little or not at all, a possible (and very common) cause is a nutrient deficiency. Make sure you use a nutrient-rich substrate (but with only a moderate amount of humus) and regular and sufficient fertilization.