Yes, Tarev, I guess the thread got a bit sidetracked, which often happens as more people join in the conversation!
Djavid, consistent moisture available to seedlings/young plants is important. Wet will rot the roots. The soil needs to retain moisture when watered, but needs to drain well so the roots are not wet. Wet soil will cause the fine feeder roots to rot. Keeping the soil on the dry side of "moist" will also prevent the "mildew" growth you are experiencing.
Also, I agree, definitely do not root prune. Not while small. You are only damaging your seedling and inviting rot. The long root is more an anchor than a feeder, but fine feeder roots will develop off the side of that root and are definitely important during early development.
You said you rarely see sun, so give your Adeniums as much light as possible. Adeniums come from arid tropical areas with little/no protection from full day-long exposure to intense tropical sun. Luckily they don't REQUIRE that much light to live and do well, but they definitely need bright light. Bright light will be especially important for good blooming when your plants are larger.
I also agree with the advice to not pinch, not while the plants are small. Pinching typically just involves removing the apical growing point. On typical garden plants with tender, watery new growth, grabbing the smallest leaves at the growing tip between the thumb and forefinger ("pinching") and pulling will break the tender stem just below those tiny leaves. This will encourage the dormant side buds to start developing. On sturdier plants, the growing tip is snipped out using the fingernail, scissors, or a sharp blade. It does not involve pinching to simply wound (crush) the tip. A clean cut can heal quickly, but crushed tissue invites invasion by disease.
Good luck with your Adeniums and welcome to ATP!
