Answer: I don't know what kinds of ferns you are growing, but if they die down in the winter and resprout each spring, why not just plan on repotting them each spring by separating the roots and replanting them? The tubers are actually nitrogen fixing nodes and they are normal on asparagus ferns so if that's what you're growing, there is nothing to be concerned about. Just repot your plants every spring and they won't be tempted to grow out of the drainage holes. Enjoy your garden!
Q&A Library Searching Tips