An example method of orchestrating a software-defined (SD) network layer of a virtualized computing system is described, the virtualized computing system including a host cluster, a virtualization management server, and a network management server each connected to a physical network, the host cluster having hosts and a virtualization layer executing on hardware platforms of the hosts. The method includes receiving, at the virtualization management server, a declarative specification describing a proposed state of an SD network for the host cluster, deploying, by the virtualization management server, virtualized infrastructure components in the host cluster in response to the proposed state in the declarative specification, and deploying, by the virtualization management server in cooperation with the network management server, logical network services supported by the virtualized infrastructure components in response to the proposed state in the declarative specification.