The best time to harvest seeds for sprouting is when they're just starting to turn redish colored. If they get too hard they won't sprout. The outer pod should still be soft and graying before you try to sprout the seed. I soaked the seed in water overnight and put in potting soil about 1 inch deep and let it sprout. It took a couple of weeks. My little tree is now about 8 inches tall and grows very slowly. I still have it in a 4 inch pot. Will change to larger pot this fall.