TIP: Water the seeds with a spray bottle every few days to keep the soil moist but never soggy. Open the plastic wrap daily to provide air circulation. Temperatures above 85 degrees F encourage germination. If this temperature cannot be maintained in a sunny window, use a heating pad underneath the seed tray.
Once the seedlings have developed their second set of leaves, transplant them to their own containers. Start with pots 3 inches wide and move into larger ones if necessary. Plant in a compost soil like the one used for germination. Magnolias like full sun, but take care to introduce your plants to it only gradually. Keep them in partial shade through the first summer.
Magnolias prefer a slightly acidic, well-draining loam. For the first few years, maintain a layer of mulch 3 inches deep around the roots to protect them. Keep the newly planted tree well watered for the first year, but never allow the soil to become soggy.