1. Extract the seed.
Carefully remove the avocado seed without cutting or breaking it. Wash the seed to remove any slippery residue, and dry it thoroughly.
2. Pierce the seed.
Holding the avocado seed upright, wedge three toothpicks around the circumference of the seed at a slightly downward angle. (Not sure which part of your avocado seed is which? The top is the slightly pointy end, or the part of the pit that faced the stem when the pit was inside the avocado.)
3. Soak the seed in water.
Fill a tall, clear glass with water. Place the avocado seed in the glass with the toothpicks resting along the lip of the glass. The bottom of the seed should be submerged in the water while the top stays dry.
4. Let the seed sprout.
5. Trim the sprout.
Once the sprout tail grows to 6 or 7 inches, trim it in half to encourage new growth.
6. Prepare to plant.
Once the sprout grows to 6 or 7 inches again, it’s time to plant it. Place the seed in a 10-inch-wide pot filled with humus-rich soil, leaving the top half of the seed exposed.