Mold and / or failed rooting on bud grafts on hibiscus

Question: Mold and / or failure to take root on hibiscus bud grafts

Good morning. I practiced gem grafting on hibiscus about a month ago (May 10th). I did things right, I tied tight with raffia or duct tape, and then, in order not to make them shrink, I also covered the bud with leaves from the same plant.
Now: one gem in particular had developed a small leaf all crumpled under the "stalk" after a maximum of 10 days. There was something white on it, like a powder, with small filaments, like those of a spider's web. Days later there was no powder, but the young leaf had dried up. I tried to cover, but it seems to be gone by now. Here in general this type of grafts is used to cover them for three weeks, usually with weed bundles. In fact I noticed that the bark flaps under the leaves or grass, remain moist, instead of drying out (and often the grafted bud is also dried). Should one perhaps seal the graft with wax or any material that does not overflow (the arbokol disappointed me a little in this sense)? What can be done against mold? Then I don't know if I should have done the grafting first, because I read that it can be done safely in the summer. Excuse all my doubts, but I am a beginner.
Thanks, and congratulations.

Answer: Mold and / or failure to take root on hibiscus bud grafts

Dear Leo,
as you have well said, the bud graft is practiced in spring or summer; in the spring the dormant buds are taken before they are enlarged; a little more difficult is the sampling done in late spring or in summer, since the choice of the gem must be made with care and attention: it is necessary to choose already enlarged buds, but which have temporarily suspended their vegetative development, waiting for a cooler and wetter climate. It is therefore not so easy to choose the right gem; in addition to this, some plants seem to guarantee better and faster success by using a type or gemstone; in particular, as regards the hibiscus, in general the grafts are practiced splitting, or with a dormant bud. As you well said, after engaging, it is advisable to cover the point of grafting, so that the bud remains moist and fresh; if possible the grafted plant should not be placed in full sun, otherwise the grafted branches will be shaded, so that they are not completely exposed to the summer sun, which dries them excessively. To cover the gem various expedients are used: there are those who cover the grafting point with damp earth; those who use leaves and twigs instead; and there are also those who use simple mastic for pruning, this substance, similar to liquid wax (often it is vinyl glue) also contains some fungicide, and therefore, in addition to keeping the nesto and the rootstock moist, it also guarantees the no fungus or mold of any kind.