Step 1: Cut the avocado in half, lengthwise, being careful not to injure the pit
Step 2: Wash pit carefully to remove any flesh. You want to leave the skin/seed cover on the pit!
Step 3: Holding the pit "narrow" (pointed) side up, stick four toothpicks into the middle section at even intervals, to a depth of about 5 mm.
Step 4: Add some water to a small glass container (i used a pickle jar) until it reaches the very top rim. Your container's opening should be wide enough to easily accommodate the full width of the avocado pit.
Step 5: Set your avocado pit (with inserted toothpicks) on the top rim of the container. The toothpicks should sit on the rim of the container, leaving the pit only half-submerged in the water. Make sure the pointed end is up and the rounded end is in the water, otherwise your avocado will not grow.
Step 6: Set the container in an undisturbed place - near a window or any other well-lit area in order to begin rooting and the growth process.
Step 7: Change the water every 1-2 days. Do this to ensure that contaminants (i.e. mold, bacteria, fermentation, etc.) do not hinder the avocado's sprouting process.
Step 8: Wait patiently since avocado takes several weeks to start growing its roots. Over the next 2-3 weeks, the avocado's brown outer layer will begin to dry out and wrinkle. Soon after, the pit should begin to split open at the top and bottom. After 3-4 weeks, a tap root should begin to emerge at the base of the pit.
Step 9: Continue to water the plant accordingly. Take care not to disturb or injure the tap root. Continue to allow the avocado pit time to establish its roots. Soon, the avocado will sprout at the top, releasing an unfolding leaf-bud that will open and begin to grow a shoot bearing leaves.
Step 10: Plant the baby tree. When the roots are substantial and the stem top has had a chance to re-grow leaves (after at least one pruning), your baby avocado tree is ready to be planted in soil. Remove the sprouted pit from the water container, and gently remove each of the toothpicks.
Use a 20-25 cm terracotta pot filled with enriched soil to 2 cm below the top. Smooth and slightly pack the soil, adding more soil as needed. Once the soil is prepared, dig a narrow hole deep enough to accommodate your avocado's roots and pit.
Step 11: Carefully bury the avocado pit in the soil such that the top-half of pit shows above the surface of the soil. This ensures that the base of the seedling trunk doesn't rot under the soil. Pack the soil lightly around the pit.
Step 12: Water your plant daily or enough to keep the soil moist. Avoid over-watering to the point that the soil becomes muddy. If the leaves turn brown at the tips, the tree needs more water. If the leaves turn yellow, the tree is getting too much water and needs to be permitted to dry out for a day or two.
Step 13: Continue to tend to your avocado plant regularly, and in a few years you will have an attractive and low-maintenance tree!
I've gotten as far as the 9th step! I took these pics a couple weeks ago and they have grown soooo much since then!
I have two different types of avocados growing...one just a regular and the other a "slimcado" which has less calories and fat than the other.
It has been so fun watching them grow!
Give it a try!!
9/22/12 update pics