My plumeria is sick !!

Question: my plumeria is sick !!

a few months ago I have a frangipani plant that my husband (tired of hearing my gripes, because I could not have one (I have already tried, as a total inexperienced, to make 2, a Balinese cutting and a Sicilian seedling, with very ruinous results) , he sent for me from Thailand.This is a cutting of "penang peach" grafted ... it was great until now; at the beginning of June he put a bunch of very green leaves and, now that the heat has arrived also in Milan ( I live about 20 km from the city), he has been living in his beautiful wheeled vase on my terrace a few weeks ago, I live in an industrial area, surrounded by low sheds and in front I have a WWF oasis, knowing that frangipane loves the sun, I put it against the wall, facing south-south west, during the day it receives a lot of light and heat, and, being an open balcony, closed only by a wall to the west, it is very airy ... So far, seems like a beautiful fairy tale, but a few days ago I noticed or of the white spots on the leaves, as if it had been whitened in drops ... I have searched in the various forums, but I have not found any description similar to what is happening to my plant, or better: on the stained leaves, there are no insects of any kind , whites or reds that they are, neither ragnateline ... not even on the tips or on the trunk!
Then, the tragedy: I ‚Äč‚Äčnoticed that the 2 oldest leaves have turned yellow, they have not changed shape (they were already arched) but have brown margins and tip ...
can you help me?
how can i send you the photos taken on my map ??

Answer: my plumeria is sick !!

Dear Bruna,
the plumeria they are plants that tend not to suffer from attacks of various types of parasites; clearly, the specimens that do not find ideal cultivation conditions, tend however to fall ill more easily; in your case probably the leaves are affected by some fungal disease, which is cured by vaporizing a broad spectrum fungicide mixture on the whole plant, choose a systemic fungicide, which will also be absorbed by leaves and branches. In my opinion, your plumeria suffers from the heat, because the position you have chosen does not allow a correct exchange of air. We often suggest to those who grow exotic plants in northern Italy, to place them, during the cold months, near the walls of the house; this advice is given because the walls tend with the sun to heat up a lot, even in January, and during the night hours they release the heat, creating a sort of greenhouse climate. Clear that such a position is perfect for your plumeria during the first months of autumn or at the end of winter, when the minimum temperatures will be mitigated by the walls of the house exposed all day in the sun; but in the height of summer, a warm wall, which takes the sun for many hours, remains warm throughout the night, creating a situation similar to that of the oven, which certainly does not benefit the plumeria. So, in addition to vaporising with a fungicide, if possible move the plant, an area well exposed to the sun, where it can enjoy an excellent exchange of air from all sides (I understand that on the terrace it is not always easy to find the perfect position for all plants). The position you described will instead be perfect when the cold arrives, as it is unlikely that the nocturnal minimum will suddenly fall below 10 ° C, thanks to the walls heated by the sun. Yellowed leaves and dry margins can then be symptoms of various problems, from the deficiencies (or excesses) of fertilizer, to shortages (or excesses) of watering. The plumeria they are large shrubs, which ideally would like to live in a large garden, in full ground; the conditions present in a vase on the terrace are hardly those ideal for the plant, which needs regular watering during the summer months, especially if it is positioned near a wall that heats it even at night.