They almost looked cooked. Those temps are very high. What temperature is it on the seedlings when the sun comes directly through the glass? And I see they are on foil trays too.

Hi Floral, here are 2 more photoS with the leaves in focus so you can see it better. It doesn't seem "cooked" but perhaps on the dry side but then again, I don't see the leaves curling inwards that show dehydration as I have read.

(Picture 1: Orange seedling)

(Picture 2: Lemon seeding)

Yes, I agree the temperature is on the high side but after googling around, I read that they can survive or thrive even when the temperatures are higher.

Temperatures of direct sunlight around 11.30 in the morning with the window open is around 39C/102F. However my plants are shielded by the window and due to their position, do not receive direct sunlight after around 10.30. I'll try to get a reading of the temperature again tomorrow.

They indeed are on foil trays only because I don't have anything else to collect the water in. The rest of my seedlings are placed in similar conditions and seem to be doing well so far.

Check for root rot.

Steve

Hi Steve, I dug up some of the soil to check out bits of the roots in the first 2 pictures but it seems fine to me. But then again, I'm quite new to this so perhaps I might be wrong.

Would I have to uproot the whole seedling in order to properly determine whether there's root rot? I would like to avoid that if possible because I've read that plants go into a bit of a shock when they are transplanted so I imagine this would have a similar effect.

Certainly looks like rhizoctonia root rot, more or less common in seedlings.

Hi Silica, since you and Steve have both suggested that it might be a form of root rot, I'll uproot my orange seedling for a look when I get back because I think it's a lost cause already.

So I uprooted my seedling to take a look at the roots but there does not appear to be any rot to me or at least I can't tell if there is any. Below are some pictures of the plant.

Remove the leaves and the stem should bud out.

Hi Steve, I can give that a try. I've always wondered though, if the leaves are removed, wouldn't it's ability to photosynthesise be taken away? If so how does it have the strength and energy to produce more leaves?

Also having seen the plant in its entirety now, would you know what caused it's decline? Seeing as there does not appear to be root rot, it probably is not an issue with overwatering right?

Notice all the ""J" rooting and the sharp bends in the tap roots. That is because of the type of medium the plant is growing in. Also there is no sign of any development of root branching. Looking at the medium, it certainly does not look anything like a seedling mix.

Hi Silica, I had germinated the seeds in a ziplock bag and only placed them in soil after a bit of root had emerged. Perhaps that might explain the word curves at the start.

I didn't know there's a special mix that seedlings should have. I went to look for soil and this black potting mix was the one I could find. The 90 degree bend at the end of the root was because the root had reached the bottom of the container. Given what you've said, I take it that the soil is the cause of the seedling's decline?

Also thanks Steve. It's reassuring to know it's all those bends in my roots aren't a big issue.

Steve, all commercial citrus nurseries would discard all seedlings that developed the curves you show in your above pictures.

Hi Steve, would growth be inhibited if I do not remove the current set of leaves?

I don't know but probably not. You can leave them .

Steve

Silica I know but I don't have to and they grow fine. The smallest picture is of a fukushu kumquat that is now 5.5 feet tall and 4 feet diameter so thick you can't see through it. Seed grown and fruiting last year and about to flower this year.

Steve

They got too hot. Keep seedlings cooler.

Hi Steve, I've gone ahead to remove the leaves since they seem to be getting more yellow. Should I be removing part of the stem too? The top bit seems a bit flimsy.

Hi Dave, I would if I could but unfortunately the temperature doesn't go much lower. The best I can do is shift them out of the all direct sunlight. I've read somewhere that seedlings generally don't need any or much sunlight. How true is that and true till what point?

Seedling grow off their seed pod until it is used up. Don't cut any more off. They will either grow or die. I lose a lot of seedling like that too.

Steve

Thanks Steve. I'll leave it as it is. If the plant still has a fighting chance, how long would I expect it to take to bud again?

Also a question an another one of my orange seedling which initially failed to germinate for perhaps a month after me trying to kickstart the process until I removed the outer coat of the seed. It was a small seed to begin with and after it sprouted, it sort of did not grow much after. All of my previous seedlings I had watered a bit everyday but after I learned that citruses like to dry off before being watered, I only watered once every few days.

This was how it was on 19 April

This was how it looked on 10 May.

Seems to be growing way slower than all my other seedlings. Do you think this could be inherently the case due to the smaller seed or is this a watering issue?

About 2 days ago it appeared to be declining. The biggest leaf had always been extremely perky, standing almost vertically to catch the light from the window but recently it flattened and appears to have a very slightly yellow edge. Today it appears to have lost more of its green to appear more yellow. Is this a watering issue? Appreciate all your replies and input so far! These setbacks makes me feel like I don't have the ability to grow plants.

Citrus seedlings are very hard to get going. In my first attempt I had 1 seedling kumquat survive out of over 300 seeds.

Hi Steve. When you say they are difficult to get going, do you mean to germinate or to grow bigger? Looks like I have the opposite situation as you since the temperatures don't ever get cold, only hot.

I've read that at an early stage of growth such as mine, the plants would not need any fertiliser. At which point would fertiliser then be needed? Was wondering if the slow growth has anything to do with nitrogen deficiency.

The seedlings can do fine as long as there is still the seed left to provide the nutrients. Afterwards you will have to provide its needs. Cold is a big problem for me.

Steve

How can I tell if the original seed is able to provide the nutrients still or is just an husk that's still attached?

My recommendation is to toss those seedlings, and start over using a much better medium. Don't waste your time, the seedling shown in your pictures are off to a disastrous beginning,

which will effect the trees future development.,

Keep the seedling but start over with a new batch and better medium. Use the better medium for your current batch to.

Steve

It will shrivel up to nothing.

Steve

Hi Steve and Silica. Thanks for the input. So it seems like the issue is with my soil? Yes, I wouldn't want to waste my time and reviving my plant if it is already impossible. What should medium should I be looking for? Any recommendations for the medium then? I heard there's probably a mix that's simply called citrus mix. Is there a suitable mix that simply goes by another name in case they don't call it that where I am?