Looking for any advice...

I've had these seedlings growing indoors for the duration of the (never ending) winter. This is one of a couple that seem to be doing this. They grew nice albeit slowly and then the foliage rapidly started to brown and die back. They seem to continue to put up a leaf that then just dies in short order.

I can find no indication of insect activity and nothing that externally indicates a problem with the plant. The crown is firm.

Is it a dormant seedling trying to go to sleep? I'm really at a loss.

Some of mine are doing the same thing , which never happened before. It's due to the long cold winter. The furnace is running longer and the air is drier. It's basically poor air circulation. Use a small fan to move the air around the plants. Don't over water.

It does seen illogical that a plant so young, in a controlled climate, would go dormant.

Try a 10% hydrogen peroxide solution on one plant to see if that stops this behavior.
And of course, that is 10% using the 3% peroxide less-than-one dollar bottle.
Use this mixture as the plant's regular watering.

Could also be the start of damping off. I think that's why profesora is telling you to use the hydrogen peroxide.

I have a fan running in the room. I've always read that damping off will only affect seedlings that are just sprouting?

I could put some dilute peroxide and see if that helps.

What is the light intensity? How long are the lights on (daylength)? What is the temperature?

Can you take a photo of the centre of the fan from relatively close above it? Is there a small leaf visible in the centre?

Although the crown is firm, is it possible that the roots have died - could those pots have been over-watered?

I don't see a new sprouting leaf in the centre of the fan, which I would expect to see if the fan is actively growing. It looks somewhat as if the fan had stopped producing new leaves quite a while ago and that the leaves it had produced are reaching an age at which they would die and dry up. If that is the case then that would mean the fan is dormant.

Look like my 2013 prolifs in a south facing window.

Here's the picture of the center of the fan. It's still growing - the green and half dead leaves were both grown over the last 2 weeks.

The lights are on for 14 hours a day most of the other seedlings and the other plants are doing fine with the setup. Temp varies from 64 at night to 68-70 during the day. I have been letting the soil dry some between waterings. I might pull it out and rinse the crown and see of there is anything obvious.

JWWC said:Here's the picture of the center of the fan. It's still growing - the green and half dead leaves were both grown over the last 2 weeks.

Thank you for the photograph. It is not trying to go dormant. The leaves are aging, (senescing) but they do not seem to be senescing normally. It appears that the tips of the leaves are senescing but that the bases remain green for longer and are senescing much later. I would have expected the entire leaf to start to yellow before becoming as dry as the tip portion of the leaves in the photo.

JWWC said:The lights are on for 14 hours a day most of the other seedlings and the other plants are doing fine with the setup.

A day that is 14 hours long should be enough to keep it growing. Although the other plants are doing fine with the same setup, because every cultivar or seedling is genetically different, there can be plants that are not fine with the same setups. I would expect that to be less likely with a 14 hour day but more likely if the day had been 12 hours long. The day length is not likely to be a problem.

JWWC said:Temp varies from 64 at night to 68-70 during the day.

The temperature seems warm enough for daylilies to grow well. Some daylilies I have growing at 59F (during the day and cooler at night) are growing so slowly that it is very difficult to see that they are growing at all but they are not drying or senescing in the same way as the one in the photo. The temperature is not likely to be a problem.

Are the lights incandescent or fluorescent or something else? How close to the leaves are they?

How many plants are showing this problem? Is there any pattern to which plants have the problem, by location, by ploidy, by age, by soil, by pot size, by registered foliage (DOR, SEV, EV), by parent, etc?

Hazelcrestmikeb said:Look like my 2013 prolifs in a south facing window.

That might suggest that less than adequate roots or water (because they are prolifs) and high heat and light during the day (because it is a south facing window) is causing the problem - "burning" the foliage ?

Maurice, I am sure that you are right. I brought them in because it was too late to plant them outside. I start my seeds indoors between late Feb and the end of March. The idea is to get them in the ground once they reach a certain size. I find that if I plant them earlier they just reach a stage where they stop growing. I use a heat mat and fluorescent adjustable lighting with a timer.

Hazelcrestmikeb said:I find that if I plant them earlier they just reach a stage where they stop growing. I use a heat mat and fluorescent adjustable lighting with a timer.

Ok. that stop growing is interesting.

Do you know how many leaves they have when they stop growing? How long are the lights on (day length) and have you measured the light intensity? Do you know the day and night temperatures?

Can they experience the normal day length? That is, are there windows where the daylily seedlings are growing?

What happens later after they have stopped growing?

Looks to me like the old foliage is dying as the new is emerging.
I had a proliferation do the same thing last January, it's 12 inches tall now going gangbusters.

Maurice, the heat mat and the lights are on the same timer. On for 16hrs. There's a glass block window next to the shelf. They have about four leaves. have no means of measuring light intensity. I suspect that this is part of my problem. That's why my timing now is to get them outside once they reach a certain size.