madagascariensis from tissue culture

Aponogeton madagacariensis is an expensive and rarely available plant in Australia, but it seems some growers have had recent success using tissue culture techniques.
What appears in the shops are bare rooted plants with 2-4 leaves, smallish in size. The plants have no discernable bulbs and the crowns are poorly developed. However, they grow well at least initially pushing out a new leaf every 5 or so days.
I'm inclined to grow this type of plant under good conditions for A mad and try to strengthen the plant before resting it. But the question is how long should the growth period last before the rest period begins. We get these plants from the shops and have no sense of their cultivation history, so its a guess as to what phase they are in.
There are quite a few keen aquarists here, trying to get it right with this species. Not many can do it, which appears to be the trend worldwide. Bulb-type plants is one challenge, but tissue culture plants is another.
Anybody with experiences to share for the guys downunder?