Sourwood might not sound like something you want growing in your backyard, but this tree is not nearly as unattractive as its name. In summer, it blooms in beautiful bell-shaped white flowers that are nearly a foot long. In fall, its big glossy green leaves turn breathtaking shades of scarlet. It even looks beautiful in winter when its remaining fruit attracts birds from all over the area. However, the seeds of this slow-growing, shallow-rooted tree are difficult to germinate. The best way to ensure success with sourwood tree seeds is to plant them indoors and transplant them outside once the seedlings are roughly 1 foot tall.
Prepare the soil. Dig a hole that is 5 feet in diameter and 3 feet deep. Mix half of the excavated soil with compost. Then, fill the hole back in and mark the center of the hole.
Prepare the seedling tray in January. Fill it with a growing medium mixture that is equal parts peat moss and equal parts perlite. If you plan on ending up with only one sourwood tree, then fill and plant four or more cells. Not all of the seedlings will survive.
Water the growing medium so that it is moist, but not sopping wet. Continue to keep the growing medium moist until it is time to transplant the seedlings outdoors.
Place two to three tiny seeds in the center of each cell. If this feels too time-consuming, simply sprinkle the seeds over the tray so you get roughly two or three seeds in each cell.
Place the cover over the seedling tray.
Place the seedling tray under a fluorescent light. Keep the light on 24 hours a day until the seeds germinate in three to four weeks.
Once the sourwood tree seeds sprout, fertilize them every two weeks. Use an acidic fertilizer that is diluted according to the manufacturer's instructions for sprouts.
Thin the sprouts. Once the sprouts have developed two leaves, pinch off all but the strongest sourwood sprout in each cell.
Harden the seedlings off. Once they have reached 6 inches in height, remove the seedling tray cover and place the seedling tray outside in a shaded area. Do this in spring, after all danger of frost has passed. Leave them out there for two weeks.
Dig a 3-inch by 3-inch hole in the center of the hole that you dug in Step 1. Fill the hole with water and allow it to drain.
Lift the biggest seedling out of its cell carefully with a garden trowel.
Plant the seedling into the hole, so that it is at the same depth that it was in the seedling tray. Fill in the rest of the soil. Pat it with your hands to remove any air pockets.
Lightly water the soil so that it is moist below the seedling's roots.
Fertilize the seedling with the diluted acidic fertilizer two weeks after planting it.
Spread a 4-foot diameter circle of mulch that surrounds but does not come within 1 foot of the sourwood tree seed.