Help Sudden melting after trim, top, replant

[SmartAlec13]

Hello! This is not an urgent issue as it has long past, but now that I’ve joined this forum I’m wondering if any of you may know why this happened.

August 2025 I rescaped my tank after a move. Part of the new scape plan was a “field” of Creeping Jenny, aka Lysimachia Nummularia. I had a ton of it planted (on the left side in the pictures below), and the first two months it seemed to grow fine.

It started to get tall, and naturally some of the lower leaves weren’t looking so great, so I decided to follow the common method for stem plant maintenance; trim the tops, remove the lower stems, and then replant.

For some reason over the next month they all slowly started to melt and die. Thankfully a few survived, but I honestly have no clue why this happened.

Anyone have ideas or know why something like this would occur? I’ve done the same thing with my Rotala plenty of times and it’s fine. And since this occurrence, I have trimmed and replanted some of the tops of the creeping Jenny and it regrows just fine. (First photo is after the dying, second is before, pics taken about 1.5 months apart).

 

[CincyScaper]

Tank looks great!

@Dennis Wong had this plant in one of his recent layouts and might be able to chime in here.

From what he mentions on his website, some species like Rotala tulunadensis don’t respond well to hard, straight trims (like a flat hedge cut). They tend to do better with more gradual, frequent trimming, shaping over time rather than resetting all at once

 

[SmartAlec13]

Tank looks great!

@Dennis Wong had this plant in one of his recent layouts and might be able to chime in here.

From what he mentions on his website, some species like Rotala tulunadensis don’t respond well to hard, straight trims (like a flat hedge cut). They tend to do better with more gradual, frequent trimming, shaping over time rather than resetting all at once

Thanks! Both of these pics are a bit old though.

Could be the reason. I've never ever had the problem before, but I guess the previous times I've trimmed and replanted it, it was a few here or there, not an entire field of it like this time.