How to Grow an Oak Tree From an Acorn

One of our first lessons in how things grow is often the example of a huge, strong oak tree growing from a small acorn. Whether you're a horticulturist looking for a new challenge, a naturalist looking to attract wildlife or an educator looking for a fun lesson plan, growing an oak tree from an acorn can be a rewarding experience.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Acorns
• Plastic bags
• Natural insulating material
• Potting soil
• Moss
• 8-oz. Styrofoam cup
• 16-oz. Styrofoam cup
• 32-oz. tall container
• Leaf litter or compost from forest
• Protective fence or enclosure

1. Collect plump acorns right after they fall. Place them in a plastic bag with dampened insulating material. Close the bag loosely and refrigerate at between 32 and 35 degrees Fahrenheit. The bottom drawer of your refrigerator should achieve this temperature. Be sure your acorns don't freeze.

2. Keep acorns damp and refrigerated throughout the winter. The acorn needs at least 1000 hours of low temperatures to simulate winter and should be just barely damp. If you overmoisten them, mold will grow.

3. Plant your acorn around mid- to late April in an 8-oz. Styrofoam cup filled to within an inch of the top with an equal mixture of potting soil and moss. Tap it slightly to gently pack the soil. Punch four ¼-inch holes in the sides of the cup, near the bottom, for drainage. Place the acorn just below the surface of the soil in a horizontal position. Water the soil until it drains out the bottom holes. Keep the soil damp at all times and keep the cup on a southern facing windowsill.

4. Harden the plants around the middle of May, after the first set of leaves grow, by increasing their exposure to the outdoors. Place the seedlings outside during the day and bring them in at night. While they're outside, protect your seedlings from hungry critters by using a fence or enclosure that allows plenty of sunlight and wind to reach the young tree.

5. Transfer to a 16-oz. cup filled with a mixture of potting soil and leaf littler or leaf compost in late May. At this point, you can keep your tree outside at all times, while still making sure the soil is always damp. You can use mild fertilizers during this stage, if you'd like.

6. Relocate your tree to a 32-oz. container filled with the same mixture after the second set of leaves grow. While you are transferring it, check the main (tap) root to make sure it is white and healthy looking. Provide drainage holes and continue to keep the soil damp.

7. Shift your tree to its final home in fall. If you have deer in the area, continue to surround it with fencing until its leaves are above grazing level. You can also wait to plant it until the next spring by placing the tree in a sheltered area, such as a garage or basement, over the winter while keeping the soil damp and the temperature between 20 to 30 degrees Fahrenheit. Like the acorns, adult trees need at least 1000 hours of low temperatures to grow correctly.

Tips & Warnings

• Choose your oak type based on your climate. Choose oaks that are already growing well in your area. Pin oaks are susceptible to certain diseases, so avoid planting them.
• If your soil becomes too dry or you notice brow leaf edges or spots, immerse the entire plant in water until the bubbles stop. This rehydrates the plant and brings out any toxins in the roots from the dehydration or excess fertilizer.
• Take the tree's final size, above and below ground, into a account during the final planting. Don't plant too near houses, other trees, driveways or sidewalks.