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. MORE: Four Non-Guac Ways to Eat Avocado
  4. Let the seed sprout. Place your glass in a warm spot out of direct sunlight. Change the water every couple of days to stave off any mold or bacteria growth, and add more water as necessary to make sure the bottom of your avocado seed stays submerged. Within 2 to 8 weeks, you should start to see the sprout’s tail. Stay diligent with the water—you don’t want the sprout to dry out.
  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.
  7. Keep your plant happy with water and sun. Avocado plants love sunshine, so keep yours happy by positioning your pot in a sun-drenched area. (If it’s summertime, outside is good.) Water it often enough so the soil is moist but not soaked. (If the plant turns yellow, you’re watering it too much.) MORE: No-Stove Dinner: Smoky Gazpacho with Avocado
  8. Foster more growth. Once your plant climbs to 12 inches tall, cut it back to 6 inches to encourage new growth.
  9. Transplant—maybe. If you live in a climate where the temperature doesn’t usually dip below 45°F, you can transplant your tree to a warm, sunny spot outdoors. (March through June is usually the best time to do this, since young avocado trees can get sun damage in the summer.) If you live in a cooler climate, bring your potted plant indoors once temps start to dip in the fall. It won’t fare well in the cold.
  10. Savor the fruits of your labor. (Again, maybe.) Ready for some guac? Sadly, you might be waiting a while. Some avocado trees will mature and bear fruit in 3 or 4 years, while others might take as long as 15. And believe it or not, some never bear fruit at all. Which is sort of a bummer—but at least you’ve got a cool houseplant with an interesting story, right?
Love Guacamole  Here s How to Grow an Avocado Tree at Home   Prevention - 76