Genealogy /
THE MEANING AND RESEARCH OF MY POLISH LAST NAME, SURNAME? [4501]
Siejka - 1430 w grupie nazwisk pochodzących od podstawy siej-, por. staropolskie siejać 'siać', sieja 'ryba łososiowata'.
from root *sæ- "to sow," from PIE root *se- "to sow"
etymonline.com/index.php?term=seed&allowed_in_frame=0
The suffix -ke/ka—as in Rilke, Kafka, Krupke, Mielke, Renke, Schoepke—hints at Slavic roots. Such names, often considered "German" today, stem from the eastern parts of Germany and former German territory spreading eastward from Berlin (itself a Slavic name) into today's Poland and Russia, and northward into Pomerania (Pommern, and another dog breed: Pomeranian). The Slavic -ke suffix is similar to the Germanic -sen or -son, indicating patrilinear descent—from the father, son of. (Other languages used prefixes, as in the Fitz-, Mac-, or O' found in Gaelic regions.) But in the case of the Slavic -ke, the father's name is usually not his Christian or given name (Peter-son, Johann-sen) but an occupation, characteristic, or location associated with the father (krup = "hulking, uncouth" + ke = "son of" = Krupke = "son of the hulking one").