I live in the Bucks County area (Doylestown, PA).
Do not want to drive to these gardens but would prefer finding a local bus trip from my area.
We are not aware of any day trips of this nature, but since the clubs usually communicate among their their members, that information is not something we would be aware of.
You might want to contact the places you would like to visit -- Bartram's Garden, Mt. Cuba, etc. to ask them if they know of any groups from Bucks county that are planning day trips. You can also check in with your local library or adult school or community group.
I'm told the the Cheltenham Township Adult School runs excellent day trips and tours to places all over. You don't need to be a resident of Cheltenham Township to take these tours.
Click on "Trips and Tours"
And, of course, PHS runs wonderful daytrips to gardens. Consult our website calendar for upcoming trips. Hope this helps.