- 1). Fill a deep seeding tray with equal parts of a good seed starting planting mix and coarse sand. Water the soil well and allow the excess water to drain from the bottom of the tray.
- 2). Plant the seeds 1/4 inch deep and cover with the soil. Pat the soil slightly to firm it.
- 3). Place the seeding tray on a heat mat set at 75 degrees and allow it to stay on the mat until the seeds sprout. This should take two to three weeks.
- 4). Remove the seeding tray from the heat mat and place in a sunny area. Three weeks after they sprout, thin the plants so that they are 2 inches apart.
- 5). Transplant the seedlings into 4-inch pots, filled with equal parts of potting soil and well-rotted manure or compost, when the plants are the thickness of a pencil. Water well and keep the soil moist.
- 6). Decide where in the garden you will plant your leeks--it is best to leave them in the ground until you want to use them. They can stay in the ground, even through winter, for up to a year.
- 7). Plant in the garden when the plants are 8 inches in height. Keep the plants moist until they are established.
Source...