That depends on whether the gardener is your employee or an independent contractor. When you hire someone to work around your house or yard, that person may be your employee. The facts and circumstances determine the proper tax treatment This person is your employee if you set the schedule, control when and how the work is done, and provide the tools used. It doesn't matter if you hired the worker through an agency or if you paid him hourly, daily, weekly, or per job.
On the other hand, if your gardener is an independent contractor, he'll set his own schedule, work independently, and use his own equipment. An independent contractor usually offers his or her services to the general public.
If you determine the gardener is your employee, you'll need to file Schedule H, Household Employment Taxes, with your tax return (because you paid him at least $2,000 during the tax year). The checklist attached below lists the tasks you'll need to complete when you have a household employee. It's an excerpt from the IRS Pub 926, Household Employer's Tax Guide, which is your best resource for Schedule H information.