On March 24, 2020 an order issued by the Governor restricting the continued operation of all non-essential businesses in the state became effective. The order will remain in effect until April 7, 2020.
The provision that includes landscape services is
Workers such as plumbers, electricians, exterminators, inspectors and other service providers who provide services that are necessary to maintaining the safety, sanitation, and essential operation of residences, construction sites and projects, and needed facilities
In addition, NALP’s position can be read here which identifies the role the landscape industry is playing to protect other essential critical workers while also protecting public health and safety.
The Order: https://www.mass.gov/doc/march-23-2020-essential-services-and-revised-gatherings-order/download