60:1 When one sees fruit trees in bloom, he recites a bracha to the effect that G-d lacks nothing in His world, that He has made good creations and good trees, to benefit humanity. (See a siddur for the actual text.) One only recites this bracha once per year (even if he later sees other trees in bloom – Mishnah Brurah 226:3). If one delayed until after the fruits are already grown, he may no longer recite the bracha (even if he didn’t see trees in bloom earlier, though some permit one to recite the bracha until the fruits ripen – MB 226:4). 60:2 The bracha “Oseh maaseh bereishis,” that G-d made the works of creation, is recited on seeing a meteor (AKA a “shooting star”) or a comet, on experiencing an earthquake, on mighty winds, and on lightning. One only recites the bracha on a meteor once per night, even if he should see another one. One only recites the bracha on seeing a comet once every 30 days. If one hears thunder after lightning, he recites the bracha “shekocho u’gvuraso malei olam,” that G-d’s might and power fill the world; if he experienced the lightning and thunder simultaneously, he only recites “Oseh maaseh Bereishis.” Similarly, if one heard thunder while he was reciting “Oseh maaseh Bereishis” on seeing lightning, he does not recite a second bracha because it is included in the bracha on the lightning. One only recites the bracha on thunder or lightning immediately after experiencing them; if one delayed, he does not recite them.