Neomarica candida

[CG100]

I have had two plants for something like 5 years or so. They are houseplants which grow in semi-shade (amongst other plants) and get down to around 10C on a cold winter night, as a guess.
The plants have clustered (formed offsets) to a minimal degree and the main plant has grown upwards in a fan (it reminds me of a long-leaved Crassula Buddha's Temple).

Over the past several months, the "trunks" have started to look rather sickly and I am pretty sure that one will depart even though I have broken it up a bit and replanted in the hope that something will root.

They have flowered and produced the usual plantlets, which I have hung onto, fortunately, so not a total loss.

Does anyone grow the genus or species well (or at least trouble-free and over a long period), and can tell me their method?

[Uli]

I grow several different species of Neomarica in the open garden in southern Portugal. Maybe not Neomarica candida but Amongst others Neomarica northiae. Some in dappled shade and some in full sun which doesn't seem to matter, those with more exposure to sunlight flower better. They are in the irrigated area of the garden. For me they are plant and forget kind of plants. However they never form trunks but they clump, so I cannot comment on that. Maybe it would strengthen your plant if you bring it outdoors for the summer?

[CG100]

Many thanks @Uli

From that, I may be killing them (slowly) with kindness.

Irrigated area - stays damp or irrigated just enough to prevent total dryness?

[Uli]

As water is a precious resource here in Portugal, I try to keep consumption as low as possible. The irrigated area I mentioned receives water three times a week for about half an hour during the night. The time does not really tell you much about the quantity. Right after irrigation the spot is damp but with dense plantings and this being under or close to our old cork oaks all the available water is quickly absorbed and the soil goes fairly dry in between the waterings. Not all the plants can cope with this regime so natural selection will take place. But I do not want to increase the amount of water being used. The Neomaricas seem to be able to tolerate relatively dry soil in between the waterings once established but might do better with more water. Even potted plants do not suffer significantly if they might get dry in between (which is not intended)
Sometimes, in very hot and/or windy conditions I top up the water for some plants by hand with a watering can but obviously this is not being done regularly.The Neomaricas don't need that.

[CG100]

Many thanks again @Uli - I will change things to being drier and use better-drained compost.