how tall grow these plants ?

[eminor]

Hello, there is a lot of various answer on internet to know the maxiumum size of a plant, some say that walichii grow 20cm max, others say 45... is there anyone can tell me what the maximum size these plants can grow ? thx so much

• Rotala walichii
• rotala macandra
• hygrophila difformis
• didiplis diandra
• pogostemon erectus
• hetheranthera zostefolia
• blyxa japonica
• bacopa caroliana

 

[Guest]

I tend to use Tropica’s online plant catalogue for reference. It’s always pretty accurate. However, macrophytes and often plants in general exhibit a fair degree of developmental plasticity in response to different environmental conditions, which is probably why you’ll find a spectrum of different answers on the internet.

 

[Hufsa]

The problem with reporting height on stem plants is perhaps that they just grow and grow upwards until they inevitably reach the surface?
Ive honestly never come across a stemplant that stops growing at any point. Except Blyxa japonica I suppose which bushes out a lot more, but that one is a bit of a special case as far as stemplants go.
So how do they even determine those arbitrary heights? Is it when the plant gets so long the bottom part rots away completely? I think it would take a pretty deep tank or a crappy setup to see that happen.

If the main reason you want to know how high the plants get is because youre gonna put them in a smallish tank, I think it would be far more useful to look at growth rate.
Something that grows the speed of light (Heteranthera or Hygrophila) is gonna be much harder to keep mowed down to a suitable size.
One not on your list but unusually slow (in a good way) for a stemplant is Myriophyllum sp. Guyana. That one would be a pretty suitable stemplant for a small tank just based on its moderate growth rate and small diameter.

 

[erwin123]

Eriocaulons are usually considered to be slower growing that most other types of aquatic plants.

After moving to a fortnightly maintenance schedule I am also reconsidering what plants to have, so that their growth rate coincides with my fortnightly maintenance schedule. A.Pedicatella fits the bill of something that grows relatively slowly and thus only needs fortnightly instead of weekly maintenance.

 

[Conort2]

I don’t think there is a limit with stems. I let some rotala wallichii go wild recently and the stems must’ve been over 60cm long and I’m sure they would’ve kept growing if I let them. I’ve also had myriophyllum Guyana get to similar lengths and that is supposed to be a smaller growing stem.

Cheers

 

[Hufsa]

I’ve also had myriophyllum Guyana get to similar lengths and that is supposed to be a smaller growing stem.

For sure, it will get just as long as the others. But it usually takes longer time to get there 😁

The same cant be said for all the other species of Myriophyllum, those grow way too fast in a CO2 injected tank, I think this is why they are not more commonly seen in such tanks.
It amuses me that what makes a stemplant good for low tech (grows relatively fast and easy), makes it a "bad" stemplant for high tech (needs trimming twice a week) 😅