Beautiful plants Alain. When I first looked at them I though they were L. dorotheae! L. julii subsp fuller var. brunnea are great looking plants. Wonder why I've never grown them??? Maybe I'll sow a few seeds next spring. What's your soil mix for lithops? I've moved away from any organic component, but I think I really under water my lithops spring and early summer. I've considered using a small amount of coconut husk fiber (coir) in my mix to hold a little extra water, but I guess I could just try and water more often. :)
I find it difficult to choose what seeds to grow and end up with too many. I find the MSG have a good list and the IAS some odd things I should not try but do.The soil mix I use is John Innes [which is loam based], sharp sand and aquarium gravel. I do not believe John Innes is available in the USA. I have not tried much in the way of different mixes as what I use seems to work. I did try peat based compost at one time but found it difficult when restarting watering.