apple flowers

The beginning of the flowering of apple trees is a scientific indicator of spring - or the growth period - beginning. I thought I got an apple and a pear these days, but now looking at the flowers at home I fear that both are pear flowers.

Anyway, apple and pear flowers show approximately at the same time in spring, with pear being usually a few days earlier. (And I will search for a proper apple tree in full blossom in the next few days, promise!)

Now, the statistics are as follows (according to Diercke Weltatlas Österreich, Wien 2000: p. 53; based on the average occurence of full blossom of the last decades), where of course you have to allow for a divergence of up to two or three weeks between individual years (according to variations in the weather which are completely normal):

• apple flowering begins up to and including 31.03.: in the warmer coastal regions of Spain and Portugal
• up to 10.04.: on all coasts of the Mediterranean
• up to 20.04.: in Bordeaux and the Atlantic coast north of it, in the Po plains, in Bukarest and Wallachia and also in the Hungarian lowlands and in Budapest
• up to 30.04.: in Southern Ireland, London, Paris, Rhine valley (from Cologne up to the Swiss border at Basel) and Vienna, also on all coasts of the Black Sea
• up to 10.05.: in higher lying regions (~400 metres above sea level) of Central Europe including Bern, Prag, Berlin, Warsaw and Kiew, as well as in the northern parts of Ireland and the English midlands
• up to 20.05.: in Central European regions up to ~700 metres above sea level (including Munich) and in Northern Europe up to the coast of the Baltic Sea
• up to 30.05.: almost anywhere in Europe where apple trees still grow, except regions around about 60° latitude and north of it (so Scandinavia and Russia north of Saint Petersburg)

So, in Vienna, apple trees aren't supposed to flower before approximately 20. - 30.04 - which could possibly vary by about 2-3 weeks (that is, 1-2 weeks earlier or later, so a span of about 15.04. - 05.05. maximum). These photos were taken on 30.03. and 01.04., but as they both seem to be pear flowers I'll yet have to find an apple tree to proove that this year indeed the vegetation period begins very early.

Anyway, here is a link to a pdf-file in German about the development of the vegetation period in recent years which shows that indeed the apple flower now begins significantly earlier than twenty years ago; it shows figures only for Germany, but in the Rhine valley which is, climatically, only slightly warmer than Vienna once the apple flower only began around 25.04. but in recent years does so even before 20.04.

Whatever, this year's apple flowers seem to mark a record (there surely must be apple trees around here in Vienna, flowering). The climate change taking place also is evident - this year certainly would not be proof enough, but there already are plenty of other works proofing it, like the pdf linked above.