Future wireless sensor networks (WSNs) are projected to run multiple applications in the same network infrastructure. While such multi-application WSNs (MA-WSNs) are economically more efficient and adapt better to the changing environments than traditional single-application WSNs, they usually require frequent code redistribution on wireless sensors, making it critical to design energy efficient post-deployment code dissemination protocols in MA-WSNs. Different applications in MA-WSNs often share some common code segments. Therefore when there is a need to disseminate a new application from the sink node, it is possible to disseminate its shared code segments from peer sensors instead of disseminating everything from the sink node. While dissemination protocols have been proposed to handle code of each single type, it is challenging to achieve energy efficiency when the code contains both types and needs simultaneous dissemination. In this paper we utilize an adaptive buffer management approach to achieve efficient code dissemination in MA-WSNs. Our experimental results show that adaptive buffer management can reduce the completion time and the message overhead up to 10% and 20% respectively.