The slow-growing Korean fir (Abies koreana) can be a lovely landscape addition with its short, wide needles streaked with silver underneath and purple cones that form during the winter. Although adaptable to bonsai culture, the tree grows best outdoors in U.S. Department of Agriculture hardiness zones 5 and 6 as well as some coastal regions of zones 7 and 8. Seed germination rates are low, according to bonsai specialists at Kitsune Bonsai; therefore, you may want to plant more than one Korean fir seed.
Dust the seeds with a powdered fungicide. The easiest way to do this is by using a small paintbrush.
Fill a 6- to 10-inch planting pot with sand, perlite, vermiculite or a combination of the three in equal parts. Moisten the planting medium with water.
Push the Korean fir seed 1 inch deep into the planting medium.
Place the pot in a plastic bag, seal it and place it in the refrigerator. Allow it to remain there for six weeks. With the plastic bag acting as a greenhouse, the planting medium should remain moist. Check the planting medium periodically, though, and dribble some water over it if it appears to be drying out.
Check the pot after four weeks to see if the seed has sprouted. If it has, remove the pot from the bag and the refrigerator and place it outdoors in a spot sheltered from direct sun exposure and harsh weather. Keep the soil moist at all times until the young tree is transplanted into its permanent location.
Fertilise the fir seedling when it has three small sets of new branches. Use a 10-10-10 liquid fertiliser diluted to one-fourth the strength recommended on the package and drench the soil with it. Apply fertiliser monthly until the seedling is transplanted.
Transplant the seedling into its permanent location when it reaches at least 6 inches in height.