6LoWPAN enables IoT and WSN devices to connect to the Internet. The traffic caused by this increase of machines connecting to the Internet can overwhelm networks, leading to congestion. SDN, with its architecture that decouples the control plane from the forwarding plane, provides novel ways of dealing with network congestion as it allows easier manipulation of the network and its traffic flow. Taking advantage of the delay- and loss-tolerant nature of WSN traffic, this work utilizes SDN to introduce an adaptive algorithm that delays sensor-generated data traveling through a network depending on the network traffic conditions with the goal of reducing losses caused by network congestion. Results from the experiments show that the algorithm reduces the loss of sensor-generated traffic regardless of the presence of non-WSN traffic in the same network, thus showing how SDN, along with delay introduction, can be used to mitigate losses in a network.