How much should you tip for lawn service at Christmas?

If this is your regular lawn care service, tip for the quality of service throughout the year , and if a one-time service, just for the single job they did.Then you have to consider if this person is an independent contractor, they should not be pricing their services with an eye to a tip. 10% is sufficient in either case, but you tip as you can afford, and to the quality and promptness of service.