Can someone please tell me what are these weird dots on my prunus and acer? Also, leaves on prunus have some light green spots and couple of theam have some weird 'things' at the 'neck' (sry, can't remember the correct word in english).
The prunus leaves appear to me as though they might have a mild rust or leaf spot type of infection. Since prunus is one half of the nearly unavoidable cedar-apple rust I tend to give them prophylactic sprays: an antifungal at least once a year (chlorothalonil, thiophanate-methyl, and Mancozeb each work well) and something that knocks down the spores no more than three times a year, e.g. copper or sulfur compounds.
The light green spots on leaves are very often related to spider mites or scales activity -sucking the sap - as sorce sugested. You may check the underside of the leaves for the bugs or perhaps their nymphs.