Two out of five rotting

[Higgs Boson]

I bought five of these (rather pricey) plants for planter box on my front porch (N.facing).

did fine until I noticed the far right one was turning black. Now the one next to it is also infected -- or whatever is wrong.

I didn't save the tag, so does anyone know the name?

Also why this is happening, and do I need to move the other 3 to avoid whatever it is?

TIA

HB

[David E. Ross]

Probe the soil. Is it soggy? Even if the planter has drainage, it might be too wet.

These look like fortnight lilies (Dietes iridiodes, also known as D. vegeta), but I can't tell for sure unless they bloom.

[Kay Lancaster]

Can't tell from the photo. The leaves look equitant, which means the plant is likely in the Iridaceae or something closely related:

be poor handling in the nursery, poor handling by you, poor planting site, fungal disease, bacterial rot... I'd start by digging up the blackened plants and examining the roots and leaves for signs of rot or infestation.

[Brooklyn1]

Gee, I don't know any answers either, could be this, that, or the moon is made of cheese... so WTF am I responding.

[Amos Nomore]

[Gunner]

The shrubs, right? Looks like a thyme. Regardless, move & clean the soil up. Watch that spot if you replant there. Just an observation from your 2 posts, consider lighten up your soils.

[Higgs Boson]

to the small round plants which are the ones that show blackening.

Responding to comments: They were well planted. Have never been overwatered. We have had only 2 rains lately; not enough for root rot in a big planter

Did well for many months. So why now? Concerned about contagion to

3 healthy plants.

This is So. Calif Coastal.

HB