Growing an olive tree from seed may not be the fastest way to get olives, but the process can be fun and challenging. To keep the quality of the fruit consistent, most commercial olives are propagated from cuttings. Olive trees grown from seed make attractive ornamental trees in the landscape and can be used as rootstock for grafting other olive varieties. A few planted olive pits will provide at the very least an attractive new tree for a patio pot or spot in the garden, and they just may produce fruits that turn out delicious.
Collect olive fruits when they are ripe, which typically is between September and late November.
Clean off all the olive fruit and wash the seed. Using a file, scarify the seed on one side. Rub the file over the seed until the tough outer seed coat is damaged.
Soak the olive seed in a bowl of cool water for 48 hours. Remove the seed and dry it on a towel for one to two hours.
Place the olive pit in a bucket filled with damp sand. Add 2 to 4 inches of sand on top of the olive pit and store it at 15.6 degrees Celsius for one month.
Fill an 8-inch pot with a mix of equal parts peat moss, vermiculite and perlite; or coir, vermiculite and perlite. Coir is a porous material derived from shredded coconut husks.
Add water to the soil mixture until it is evenly damp. Make sure the planting pot has drain holes in the bottom to allow excess water to escape.
Make a hole in the centre of the pot that is twice as deep as the diameter of the olive pit. Most olive pits are about ¼-inch around; with this diameter, the hole should be ½-inch deep.
Place the pot on a heating pad to provide consistent heat under the seed. Most garden centres sell seed heating pads. Keep the soil between 21.1 and 26.7 degrees Celsius.
Look for an olive seedling emerging in one to three months. Keep the material around the seed consistently damp with frequent light watering. Stick an index finger into the potting soil at the edge of the pot 3 inches deep to make sure the moisture is penetrating to the olive seed.
Keep the olive seedling in a greenhouse for the first year in bright, filtered light. Transplant it to the garden in the spring of the next year. Select an area that gets full sun and has good drainage.
Olives grow in Mediterranean climates where the summers are hot and dry and winters are damp and mild. In areas that freeze heavily in the winter, plant the olive tree in a large pot and drag it inside or into a greenhouse for the winter.