This statement is rather ambiguous. In general, spring tree labels can be used to mark private property, but it depends on local laws and regulations and the specific purpose and manner of marking.

If the marking is for legitimate purposes such as indicating the boundary of private land or identifying specific trees on private property for management or protection, and it complies with local property and marking regulations, then it may be allowed.

However, if the marking could potentially cause harm to the trees or violate local environmental protection or property rights laws, it would not be permitted.

It's important to research and abide by local laws and relevant regulations before using spring tree labels for marking private property.