looks like the bottom of a 2 litter... with sandy dirt in it ...

though they might thrive in such in the ground..

that mix.. does not drain properly in a plastic pot ...

sunshine might also heat the soil mass ...

be nice to know where you are.. and its cultural siting ....

ken

opps..

google Al's gritty mix.. and refer back to GW.. for hundreds of posts about media.. and how to manipulate it to perfect water management ...

trees prefer a sip of water .. and near full draining.. with little retained water ... not sodden sand .. or peat reinforced with sand ...

ken

gardengal48 it's a mix of dirt, sand and clay

ken_adrian Adrian I live in Batna, Algeria, we have native cedrus atlantica trees but they grow in higher altitudes from where I live, it's been quite hot the past days though I don't think heat is the reason I keep it in a shady place.

ken said it - sandy dirt will work well for these trees when growing in the ground but not when attempting to grow them in a container. You need potting soil or what's referred to as a soil-less mix, not garden soil. Something that is very textural and fast draining. I could go on to explain all the technicalities of 'why' but really the only thing that is hindering the growth of your seedlings is what they are growing in. Change that and you will have success.

gardengal48 thank you, I'll see what I can do