Thorny tree hedge - the city as an encroaching neighbor

Even though the term Heister was unknown to me until an hour ago, I want to speculate: The property boundary is identical to the usage boundary (Knödellinie) in the development plan. The planting requirement therefore only applies to the municipal property, which is designated as a public green area according to the land use ordinance. The city is and remains the owner of the meadow and is responsible for the maintenance and care of the hedge. If the hedge exceeds a height of 2m, the city must ensure trimming back to 1.50m.

If that were really the case, that would be great. Do you deduce the latter from the 150/200cm in the development plan?

What do you mean by both sides?

The northeast side and the southeast side.

The tree seedlings were only recently planted and are 2m tall? The thorn bushes were also planted?

Yes and yes. The trees additionally have a wooden beam as a "support."

We have a beech hedge on the boundary. With regular pruning, I do not observe any significant trunk expansion. And the shading at 2m height would also be tolerable.

Definitely. If it is really trimmed back like that, see above.

Are you deriving the latter from the 150/200cm in the development plan?

Yes. But that is just my interpretation. It is supposed to be a tree hedge and not a forest. According to Wikipedia, "Heister" are trees without a crown, and why should the development plan use this word if it only applies to the planting phase? Of course, this is contradicted by the fact that the seedlings are already 2m tall. Tomorrow you will (hopefully) receive binding statements from the city. Feedback welcome!

And here is the feedback after today's conversation:

Negative: The specifications in the development plan are only minimum requirements. Because it is an SPE area, the environmental office has tightened the requirements for this area. Therefore, there should actually be trees, and the density must also be ensured. The trees themselves will probably grow up to 8m high.

Positive: The city has commissioned a company that apparently made mistakes here. According to our contact person, "neighbor law must of course be observed." Including all setback areas, etc. What exactly that means, I still have to find out. In any case, the plants were planted too close and must be replanted at least 1m away from the property. The blackberries were not intended either and must be removed (whether this works is another matter; other thorn bushes must remain). A fence will be installed in the next few days.

She wants to inquire and negotiate with the environmental office to what extent it can be stipulated in the purchase contract that the trees must be pruned in height.

Thanks in advance for your information! Now I will probably study neighbor law...