Geranium Pelgardini Vancouver Centennial - pictured

squirral87k4-WvGwT

Hello

I bought some geranium pelgardini Vancouver centennial, pictured. 

It states here that they spread to 10cm whereas in other places it states 30-40cm spread. 

https://www.gardenersworld.com/plants/pelargonium-vancouver-centennial/ 

Has anyone grown these before? I just want to know so I know how many to put in a pot. Thanks. 

Dovefromabove

This site gives mature dimensions and annual growth .which may help   

https://www.jparkers.co.uk/geranium-pelgardini-vancouver-centennial-1017054c