I have a sapling oleander for 5 years in pots (vase diam 35 height oleander 1.3 meters) is in the sun from noon onwards ... is making a lot of yellow leaves which then loses ... what should I do?
oleanders are large shrubs, or small trees, originating in Asia; they have been cultivated for so long in the Mediterranean areas, to have become in many spontaneous places, and therefore they can be admired in many areas of Italy also of wild or wild flies. They are easy to grow shrubs, especially due to the fact that they do not fear drought, and summer heat, and are therefore very suitable for growing in low-maintenance gardens. If grown in pots, they may have problems, due essentially to the soil contained in the pot: the earth we use to cultivate our potted plants, tends to deteriorate over the years; on one side, with time the plant absorbs all the mineral salts contained in the soil, and therefore it is essential to add them periodically, using fertilizer; in addition to this, if a plant remains in the same pot for a long time, the soil also tends to modify its dough, as it is not periodically softened and lightened by the decomposing material; which instead happens in the garden soil, where the leaves fall each year, or where earthworms and other insects spend their days. It is therefore necessary to periodically repot the plants cultivated in a container; not necessarily by changing the size of the vessel. In your case, the flat has been in the same pot for many years, and moreover I also believe that the container is a little small; the time has come to repot your oleander, placing it in a nice large vase, filled with top quality soil. Also check that the roots have not been damaged, as abiding in a soil that has become excessively time-hardened, it happens that the drainage gets worse over the years, and the roots tend to be hit more easily by the rots. Then, at the time of repotting, using a nice sharp shear, remove all the dark, damaged, frayed or soft roots, so as to remove any rot.