A clear plastic cover placed over cuttings or seedlings to maintain high humidity around the plant material until roots develop or seeds establish.
Dakota uses domes to protect clones from the low ambient humidity in the propagation room. Even with domes, he lost a batch of clones when heat pad temperatures were turned up too high in combination with the hot uninsulated roof environment, raising dome VPD to 1.5.
Discussed in: Ep 004