He often painted winter landscapes and sunsets at his summer home, "Tomtebo", bought in 1884 at the village of Önningeby in the Municipality of Jomala on Åland in the Baltic Sea.

After completing his studies in Düsseldorf in 1886, he invited Fredrik Ahlstedt, Hanna Rönnberg and Elin Danielson to the newly acquired Tomtebo by the Lemström canal, thus beginning the Önningeby artists' colony (Önningebykolonin).

Acke, Hanna Rönnberg, Elin Danielson-Gambogi, Edvard Westman and Elias Muukka.

[6] Westerholm lived in Turku where he died in November 1919 from a flu that turned into pneumonia.

[6] A monument, dedicated to Victor Westerholm, designed by his student Wäinö Aaltonen, was envailed by Lemström Canal near his summer house Tomtebo in 1960.