1. Collect green acorns in early fall. Choose ones that are free of worms, holes, and fungus. Ideally, the acorns should be brown or nearly black.
2. Put the green acorns in a bucket of water for a couple minutes. Discard any acorns that float.
3. Take out the remaining acorns. Place them in a large zipper bag with damp sawdust; you should be able to fit up to 250 acorns in these bags. Put them in the refrigerator for a month or longer, as needed to germinate the new oak.
4. Keep an eye on their growth. The root end will begin to crack through around early December (late fall, early winter). Once the root has cracked through, the acorn is ready to be planted.
5. Plant each acorn in 2 inch (5cm) diameter pot deep enough so the tap root can grow. Place the acorn about 2-4 inches (5cm - 10cm) below the surface with the root facing down. Water regularly.
If preferred, just bury the root, and gently tuck the acorn to one side on top of suitable rich, soft soil. This will only work if the tap root is already well established, long, and has detached adequately from the acorn.
6. After the oak has grown about four inches (10cm), which should takes less than six months, it can be planted into the ground. In the meantime, continue to care for it in its potted environment.
Ideally, the containers should have holes in the bottom that allow for drainage.
Alternatively, the acorns can be planted directly into the ground by clearing a 2x2 foot (61cm x 61cm) area and placing two acorns into that space, with one or two inches (2.5cm - 5cm) of soil on top.
7. To transplant the oak seedlings into the ground from a pot, clear a three-foot (91 cm) circle of all vegetation. The circle should have full access to sunlight and good soil. Lay a mulch of bark chip about one foot around the tree, but make sure it does not touch the stems. In the middle, dig a hole about a foot or two deep (61cm-91cm) and a foot (30cm) wide. Place the oak seedling into the hole, sloping the soil away from the seedling so that the water does not sit at the trunk of the tree. Oaks do not like water sitting on their trunks. Next, pack down the earth and water the seedling. Watch it grow over the years
8. Add stakes or a landscaping flag so the seedling doesn’t get eaten by the lawnmower or trips someone.