Transitioning seedlings from indoors to a winter greenhouse requires gradual acclimation to prevent stress and temperature shock. Start by exposing them to greenhouse conditions for a few hours each day, gradually increasing the time over a week to help them adjust to cooler temperatures and changing humidity levels.
Ensure the greenhouse remains warm enough at night, as sudden drops can harm young plants. Placing seedlings in a sheltered area within the greenhouse, such as near thermal mass or under row covers, provides extra protection during the transition. Monitoring soil moisture and airflow prevents issues like damping off or dehydration.