Hello,
I have flower seedlings growing in my greenhouse in a heated dome. Marigolds, pansies, petunias, lobelia and alysum. My problem is the alysum are tall, weak, falling over and dying and the lobelia seem to be on pause. Do I need lights, even though the greenhouse has daylight on all sides.

How tall should any seedling be?
When can I take them off the heat, my greenhouse read 3.5 oC last night.