The Cantonese romanizations for 華 and 花 are Wah and Fa, respectively.
華, when pronounced in the fourth tone in Mandarin, is exclusively used in the name of Mount Hua and as a surname.
The usual pronunciation of 華 is huá, which literally means "prosper" and is used as a reference to the Chinese people.
On the other hand, 花 literally means "flower".
It is listed 28th on the Song dynasty-era Hundred Family Surnames.