Am I legally allowed to put real flowers on a cake? Or do the clients have to put it on ,on their own?

there are no legal issues with flowers. some of them are poisonous so are no no. flowers that are safe still shouldnt really touch the cake - and should be pesticide free. usually with fresh flowers for a cake, the florist will provide them, and acessories needed, which depends on the design of the cake.
xx

Cool, thanks so much, do most places sell the flowers to the client or do the clients buy them, themselves?

Regarding fresh flowers on cakes: I give my clients 2 options,

1.they can take their cake sketch to the florist and order along with their other wedding flowers. The florist can either do the on-site arranging, or they can leave the flowers and I will do the arranging (for a nominal fee).

2.I will order coordinating flowers (and do arranging) for the cake and add it to their cake invoice.

Over the years I have learned to know my area florists. Some I will absolutely NOT allow to do the arranging on the cake ; some I have complete confidence in and they can do the flowers to their heart's content ; and some I flat out refuse to deal with!

HTH

if you allow the florist to do the arranging make sure they are using "edible" flowers, some of them do not know the ones that are toxic and some just dont care,

I had a florist start putting flowers on one of my cakes and noticed she was using stephanosis ( a no-no) when i stopped her her reply was' oh no one is gonna eat the flowers or much cake.......i was furious, and had to go tell the bride she had toxic flowers on her cake,, anyways my policy is that if you want real flowers i will put them on or let the florist arrange it with flowers from my approved list and i must be present when flowers are being placed to make sure nothing toxic is put in place.

thanks so much you have all helped out alot