Hi Kathleen,
In UK there are several varieties of 'miniature' Pelargoniums (Geraniums) available from specialist nurseries and I expect the same is true in USA. It is also true that the commercial growers use chemicals to 'dwarf' certain plants before sale.
Regards
Ron

Hi Kathleen,
You will find the definitve answer to your question in Faye Brawner's book 'Geraniums The Complete Encyclopaedia' chapter two.
This is an excellent book, well worth reading.
Ron

Oh, hell! Now I've got to go find the book, and chances are, my library WON'T have it, so I'll need to visit Amazon.......yet again..........;-)

Thanks for the tip, and I do love to read my gardening books...=)

Kathleen in TX