Hi, Rosa carriola,
I grow cues in a GH bed.
When you say disaster, what do you mean? Did the seedlings die before being planted in their final spot. Damping off can be a problem, water from the bottom to prevent the stems getting wet and use vermiculite on the surface of the pot, this prevents the stems from getting too wet.
When you get to the final potting up stage before planting out use a flimsy pot. When ready to plant out lift the plant out of it's pot, cut the bottom off the pot and replace plant. You can then plant your cues out with the pot which will act as a barrier when watering. Just water the outside of the pot which you plant is in thus preventing the stem from getting wet, hope that makes sense.