Enclosure at public street space

There are minimum distances for trees as well. It varies depending on the tree but is usually about 3 meters.

Does this mean that individual plantings like trees do not have to maintain any distance regardless of their height?

No. What is allowed or prohibited is not as clear as in neighbor law. In case of doubt, ask the road maintenance authority.
§28 Road Act - StrG
(2) Plantings and fences as well as stacks, piles or other facilities not permanently attached to the property must not be established or maintained if they impair the safety or ease of traffic. If they are established or maintained contrary to sentence 1, they must be removed within a reasonable period upon written request of the road authority by the person obliged under paragraph 1. After the deadline has expired, the road authority may remove or have the planting or facility removed at the expense of the person concerned. Paragraph 1 sentence 2 applies accordingly.

Ha cool I've been wondering about that for a while too. So as long as it doesn't compromise safety and doesn't damage the road surface, it's okay for now? Very good - so I can let our hedge towards the dead-end street grow higher than 2m. Mixed shrubs, distance about 1m and more, no through traffic there...