Leeks are a milder flavored member of the onion family, making them a great addition to any meal. They are a long-season crop and can be mulched in the fall for winter and spring harvest. Planting leek seeds is especially rewarding due to the long period of time they take to produce a harvest. Leeks are also easy to care for and require minimal maintenance. As leeks tend to grow best in cooler temperatures, planting them in the fall or early winter is a great way to ensure a successful harvest. With regular watering and mulching, you can expect a plentiful supply of leeks come springtime.