The attached link will give you the specifics about growing walnut trees from seed. The section on seed/nut germination is about halfway through the article. Basically you collect the walnuts in late September to early October when they fall from the tree. That is when they are the most ripe and will germinate the easiest. Remove the husk, plant in a seed germination mix, then refrigerate for cold stratification. You will want to have at least a dozen or two because they are unpredictable germinators. http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/growing-black-walnut/ If you wish to plant the nuts directly outside here are some basic instructions. Black walnuts are relatively easy to start from the nut. Just keep in mind that some of them do not grow, no matter how they were handled, so always plant more than you want. It works best to start them outside in the ground where they will eventually grow. The location should get at least eight hours of sun a day. If it is under six hours, chances of the tree doing well are extremely small. Walnuts produce long tap roots and that's why you don't want them in pots or you do not want to dig them up and damage the tap root. Select your Final Destination for the future-trees. Use nuts that have just fallen off the tree. The more time they remain on the ground, the less will germinate. They could get crushed or begin to decay in certain circumstances. Remove the husk from the nut. Try to do it so you don't damage the nut inside. Some husks will be greenish but some may be black and the inside portion soft, if there are husk flies that have damaged the husk. They do not hurt the nuts. Use gloves unless you want brown fingers for weeks. This is a powerful dye. Same with clothes...don't wear anything that you will be upset if it gets stained. Dig a hole only about two or three inches deep. The nut needs to be just below grade by a small amount. Make it wider than just the nut width. Place the nut in the hole and cover with the soil and firm it. The nuts need 90 to 120 days of cold stratification to germinate. That means that the cold, damp soil and the freezing and thawing get the nuts ready to germinate in the spring. So planting times as late as November/December work here in Minnesota.