I have the same problem with Alternanthera Reineckii, and Ludwigia Repens.
what I usually do is carefully up root it, dry it a bit with a pare towel,
trim off all the roots that grow from the branch splits, trim about one
third of the plant off the top, and replant or give away. I have done this
twice already and both plants are less than 4 months old.
my plants are growing soo fast i dont have room for all the cuttings!!!
defintely just be gentle with them. always try to trim right at a branch
node.

good luck,
Matt


"flupke" wrote in message
...
Hi,

i have both Alternathera Reineckii and Alternathera Rosaefolia .
Now 1 of these, i think it's Reineckii grows to the top of my tank
so it's at least 65 cm's (25'').

At first the leaves where based at gravel level but as it started
growing, the stems grew long and the leaves base remained about the
same so now the most i see is large stems

Can i just cut a portion of the stems away and replant them?

How can i prune them so i can plant more of these? Can i just
cut some of the top and plant this?

Does this work for both types of plants, Reineckii & Rosaefolia ?

Thanks