I agree. We have a new estate in our village which is a mixture of private ownership, shared ownership and housing association properties. The developers planted daffodil bulbs around a sculpture within the grounds of the development.
Last year, the flowering daffodils were trampled on and most of them were pulled up and the bulbs scattered around.
There is also a great deal of litter scattered about - soft drinks bottles, packaging, bits of broken plastic toys. Residents must be aware that their kids are leaving litter on the paths and grass and shrubby areas rather than bringing it home for disposal, but they evidently don't care and it is spoiling a nice estate for everyone who lives there.
Children need to be taught from a very early age that you don't leave litter.
They also need to be taught that you don't pull the heads of flowers, or trample on them or pull them up by the roots or pick plants from other people's gardens (and it's another 9 days until Mothering Sunday).
I was brought up in a small village that regularly won the county's tidiest village competition, We had it drummed into us at home that you don't leave litter. We also had it drummed into us at junior school and at the end of playtimes we were all expected to pick up any sweet wrappings and we weren't let back into classrooms until the playground was tidy.
It is parents' responsibility to teach their children not to spoil the environment for everyone else.
If I was the OP and I knew which neighbour the child belongs to, I would have a quiet word with the parents. I might take round a pot of bulbs for the child to look after at home and encourage a love of gardening.