To sprout the seed, remove the large seed from the center of the fruit and wash it in water. For propagation purposes, the broad end of the seed is considered to be the bottom. The pointed end is the top. Insert several toothpicks into the sides of the seed. They should be placed about halfway up the pit. Then suspend the seed in a glass of water. The bottom one fourth of the seed should rest in water.
The seed should sprout within a few weeks. During this time, periodically add water to maintain the initial water level. If it doesn't sprout within 2 to 3 months, discard the original avocado and begin another. The roots are usually the first to emerge from the seed. The stem appears later. Pot the seedling when the root system has become well developed; the roots should be at least 2 to 3 inches long.
Remove the toothpicks and plant into a 6 to 8 inch pot using a commercial potting mix. Position the seed in the center of the pot. The top of the seed should be level with the soil surface. After potting, water thoroughly, then place the plant in a brightly lit location. A location near an east or west window is ideal. Water the plant regularly. Keep the soil moist, but not wet. Fertilize once or twice a month during the spring and summer with a houseplant fertilizer.
Avocado plants grow rapidly. They often have to be discarded after 2 or 3 years because they've become too large for indoors. (The avocado is actually a tree. It will never produce fruit indoors as it may take 20 or more years to bear fruit.)
I've enjoyed starting avocado seeds for years. I use them as a house plant and when they die they get composted. Not sure they would survive as an outside tree in this climate. The planting advice above is correct. I have recently learned that topping the plant/tree would make for a more bushy plant. It works.
I think that if you want fruit you need at least two trees to cross-pollinate.
Attached is a picture of two of my avocado plants. The one on the left is lopped and the one on the right is not.
They will produce fruit without a second tree--I had one in the backyard at my old house and it was the only avocado for miles and it still produced fruit just fine. Maybe they'd produce more if they had a "friend" but you can definitely get fruit from just one.
Many years ago when we lived in New Orleans (zone 9b) our neighbor across the street planted an avocado seed. It grew into an enormous, beautiful tree...much taller than his house. It covered itself with avocados...hundreds of them I think. Our neighbor told us how delicious they were and how much they were enjoying them.
That winter we got the worst freeze I can remember in New Orleans. The palm trees, the bottlebrush trees, ...all the tropical plants, of which New Orleans was covered...froze to the ground.
...including their beautiful, fruitful avocado tree. Nope! We never got a taste of one of those avocados, but that tree gave me hope that some day I might grow one big enought to bear fruit.
Besides, this man made home made pecan Easter eggs for our kids one year and brought them over. He fed them and all the kids in the neighborhood ice cream when the ice cream man passed one day. When his garden made enormous tomatoes, he brought us over a huge tomato one day, sliced in two and covered with Italian cheese, and baked. Delicious! He was a very good man at heart.
This is truly off the subject, but he had a problem. He worked offshore and could not drink on the job. So he stayed drunk the entire time he was home. You never KNEW he was drunk because you had never seen him any other way.
One day another neighbor stopped at our curb to talk with my husband, who was out mowing the yard. He had stopped directly behind the neighbor across the street's driveway. The neighbor across the street got in his car, backed out, hit the other neighbor's car, waved and drove off.
The next day the other neighbor went to see the neighbor across the street to tell him that he would need to pay for the damage to his car. The neighbor across the street called my husband to ask him if he had really backed into the other neighbor. When my husband told him, "yes", he gave the other neighbor his insurance information to pay the damages.
It was really sad,... but it was still so funny! He just had no recollection of the incident at all.
I'd like to thank you for this thread--all of you, even the off topic stuff, which was interesting and with a couple of great recipes thrown in for good measure! I was on my way over here (from the less tropical forums where things regularly freeze) to ask about growing avocados indoors for an ambitious friend. This thread answered all his (and my) questions very thoroughly, so on behalf of my friend and myself, again, I thank you all.