So we are renting a house in Italy and there are about 7+ citrus trees on the property. 5 of them are lemon trees. . Over the past year I have nursed them with my limited knowledge of citrus and what I could find online and in some gardening books. . The house sat vacant for a very long time and I can tell they owners treat this house as a rental for some time as the trees have been very heavy handedly pruned for one reason or another. . I live in a 9b outside of Naples Italy and it's a very mild climate, rarely is ever does it touch 33F degrees. . But we do get wicked thunder and wind storms. The trees were doing spectacular mid summer last year till I got lax on horticultural oil and the leaf miners came back hard. . A week or so ago my lemon trees all dropped about 15 percent or more of their leaves. . It did get quite cold here as of late, could that be it? . I'm a bit confused because the oranges trees seem unaffected... . Also I noticed late last summer that the all of the lemon trees leaves started to get a bit green and yellow splotchy... . I thought it may have been after an online homemade oil spray, but again, the orange trees unaffected... . Early last summer I used some citrus kits from tree help.com and they loved me for it! . I didn't use the recommended spikes per trunk as I didn't purchase that many kits and wanted to play it super safe.... . So what could be the source of both problems ? . Insufficient nutrients? . Homemade oil? Cold snap? . I should also mention that I have a lovely winter harvest going on all trees.