Rotala Sunset and right trimming?

I've had the same experience.

What's more, if I trim say 10 stems, maybe 5 out of the 10 will rot, the others are fine.
Mother plant is always fine.

So it cannot be light, ferts, CO2.

Has to be something with the trimming.

I've tried to be careful and gently break off the stem from the mother plant that already has nice roots and is not well connected to the mother plant.
Same result.

The good news is that I can grow enough to form a self sustaining population pretty easily, but I cannot have a consistent long term group that gets trimmed often.
I decided to move the plants to the 180 where they might only get trimmed once every 2 months.

This way I have far more plants/stems between trimmings.

 

I also get maybe 2-5 plantlets with roots as the main trimmed plant dies off.

I also moved the plant instead of cutting it, and still have some die back, not as much as trimming, but maybe 1/3 the plants vs 1/2.

If you leave the plant alone, allow it to really become over grown, then do not uproot the mother plant, then you can maintain a good group.

 

Cuphea is a nice little plant.

the best way to deal with the R sunset is to simply allow it to grow and not trim it if you can help it. I placed it in the back ground and the single stem I had in now 15-20 tops.
I'll trim a few and see how many make it, then take those and allow another batch to grow in nicely in the 180 Gallon tank.
This will give me a large no# to cuttings to draw from to plant a nice row in the 120 Gallon tank.

 

I had the big clump uproot after a water change due to pearling and air intake.

So I have to replant it. The larger healthier stems should be better able to recover and not melt I would presume.

Very very nice and healthy stems.
So the growing conditions, eg: light/CO2/ferts/livestock/filtration etc.......cannot be the cause of the behavior and die back.
If that were the case, then I'd see much more of it on the plants, not just post trimming/replanting/moving.

 

Petex, I know you are obsessed with this plant, I suppose I am as well.

I've had some rather excellent results with my post trim success. I have 1 failure out of 10 stems, now I am at nearly 100% success rate.
It has done amazingly well in my 180 Gallon tank with very careful replanting and trimming methods, allowing the plants to get quite large before moving them/trimming them.
If I do make a cut with scissors, I leave the old stump where it's at to resprout and it often puts out about 3-6 side shoots in a week or two.

I had one stem not too long ago, now I must have 20-30.

I might grow some Cuphea again.

 

No, none of these claims support the observations.
The plants grow vigorously.

It is only post trimming shock/movement/uprooting that causes the issues.
More trace elements might confer some resistance for some species, but I'm very doubtful.

More a response to being disturbed, die back and then resprout after the cutting with new side shoots. All the observations point that direction.
What is weird, is that not all the stems do this, only a certain number.

I must have 80+ stems now. The main stem after cutting dies, but then I get 10+ new plants from the death. If I allow the plant to grow large and am careful with the roots and moving it, then it does not do this.

 

Yes, but the stems are all exposed to the same concentration of nutrients, same light, same CO2. Not really anyway to say they are deficient vs the stem right next to the other.

Sounds like the plant you got was emergent growth.

I'm not sure why emergent growth can survive better, but many of the cut stems seemed fine in my tank, only a few did die back.
The green emergent growth also followed a similar pattern: new red growth sprouted from that green plant and I ended up with 10-12 stems after 2 weeks.

There are no studies on Rotala's I'm aware of for nutrients. This is rarely done these days in Science, in the 1980's and before, it was popular. Then mostly with weeds of concern economically.

 

Not likely any transport issues.

There are ample roots on the stems that die back, we also have stems with say 5-10 branching tops, some 10-15cm long with full roots, and one of those will die, but the others are just fine.

So the base main stem is not controlling that.

If you plant a "cut" stump in higher flow with decent CO2 etc....the plant will sprout perhaps 5-10 new tops and grow and grow without ANY issues.
After 1-2 months, you have a nice large bunch 30cm and perhaps 10-15 tops.

I've taken newly stunted tops and replanted them in the higher current areas in the Starougyne and they die back, but the new tops sprout at the nodes and those plants form new roots etc.
This way even if I get die back, I can easily propagate a lot more stems that are healthy and nice if I catch the die back fast.

So I might lose 1-2 stems, but after a few weeks, I gain 10-20.

I'd prefer more control and no die back obviously, but.........I can at least produce a lot of plants.