An Etymological Dictionary of the German Language/Annotated/Krieche
Krieche, feminine, ‘early sloe,’ from the equivalent Middle High German, feminine, ‘early sloe-tree,’ Old High German chriehboum; compare Dutch kriek, feminine, ‘wild cherry.’ Phonetically it might be derived from Old High German Chriah, Middle High German Kriech, ‘a Greek,’ if *grœca could be found in Middle Latin denoting the tree and the fruit. The word must hare been introduced from Italy, on account of the Latin term (compare Kirsche), for it is inconceivable that the Germans, of their own accord, and without foreign precedent, should lave termed the fruit ‘Greek’ because it was imported, as we assume for the moment, from Greece. At all events, the name has not yet been explained (compare further the French loan-word crèque).