The additionalJOptions parameter allows you to pass additional parameters to the underlying Java runtime.
<project> ... <reporting> <plugins> <plugin> <groupId>net.sf.jfxdplugin</groupId> <artifactId>maven-javafxdoc-plugin</artifactId> <version>1.0</version> <configuration> <additionalJOptions> <additionalJOption>-Xmx32m</additionalJOption> </additionalJOptions> </configuration> </plugin> </plugins> ... </reporting> ... </project>