Consider service warranty or service guarantees on pruning, treatments, and freshly planted trees, with clear terms and timelines.

https://mighty-wiki.win/index.php/The_Ultimate_Guide_to_Choosing_a_Tree_Service:_From_Pruning_Practices_to_Stump_Grinding_Quality

Think about guarantee or service assurances on pruning, treatments, and newly planted trees, with clear terms and timelines.