My ferns must be broken, because a year after putting 5 leaves in I had to pull a load out because they were overgrowing my tank!
Not sure what your point is? A year to take over your tank is pretty slow, something like jungle val can take over your tank in a few weeks if not kept in check (another potential plant by the way).
Given decent ferts and light it will grow bigger and quicker than without. They can get to well over 30cm tall with leaves being over 3cm wide on a standard java fern. There are smaller variants like the narrow leaf which may be more appropriate.
I am not suggesting you need to go out and spend loads on a 'high light' setup with CO2 etc. But a 'decent' light capable of growing plants is required to succeed in growing plants, most good quality tanks these days do come with one these days (Juwel, Fluval etc).
Also to have success with plants you do need to make sure they are well fed, be that with a liquid fert, fish load, root tabs or from the substrate. It doesn't really matter where it comes from, it is just much easier to achieve a lush planted tank with minimal algae by dosing ferts and doing water changes.
You can tell when a Java Fern is not getting though food when old leaves get brown spots on them and eventually die back as new ones appear. A well fed java fern will just keep getting bigger and bigger with minimal leaf loss.
Bolbitis behaves in a similar way, those can get massive.