My sister and I are going on the Munich, Salzburg and Vienna tour the end of April- early May. In our free time we are interested in visiting any gardens that would have flowers in bloom. Any suggestions for those 3 locations would be appreciated. Thank you!
I suggest Mirabell Gardens in Salzburg. They were beautiful (even in the rain) when I visited in early June. Not only can you reenact portions of the Sound of Music, they also have a garden with dwarf statutes which is super fun if you're a short stature person (see: https://www.salzburg.info/en/magazin/scenes/in-the-realm-of-the-dwarfs-the-salzburg-dwarf-garden_a_274269)
In Munich 1. English Garden 2. Nymphenburg Palace and 3. Schloss Schleissheim
Not much to do with gardens other than raising a cut fir tree, but do make a Maibaum Fest. Find a smaller town outside of the larger ones you name. They are usually in the mornings. 10:00-14:00.
Munich:
In the city center, the Hofgarten, behind the Munich Residence.
The Nymphenburg Palace Park is beautiful in spring. The video linked by Uwe is a winter recording. Right next to it is the Munich Botanical Garden. Both can be easily combined and would be my first choice.
In my opinion, the most beautiful park in Munich is Westpark. Tourists rarely go there because it is a little further away. There is a rose garden in the eastern part of Westpark. However, the end of April is probably too early for the roses to be in bloom.
Vienna:
In the first district, the garden in front of City Hall and the Volksgarten right next to it.
The Belvedere Palace Gardens are also close to the city center.
And, of course, the Schönbrunn Palace Gardens.
Salzburg:
Mirabell Gardens is the logical first choice,
followed by Hellbrunn Palace Gardens if you're heading that way.