I can't get java moss to grow, but I have swords in my tanks that are out of control huge. I bought one or two awhile ago and have split them a ton of times. Just two days agao I gave away 8-6" plants I split off the other two which are still huge. I am not a fan of the plants in the tanks though. I like them for sucking up excess nutrients, but I do not like the look in the biotype. just my personal preference.