How to Transplant Leeks

Set the leek seedlings outdoors to "harden off" one week prior to planting in the garden. This process allows the leek transplants to adjust to outdoor temperatures. Begin the hardening off process by setting the seedlings in a shady location outdoors. Keep the seedlings in the shade for the first half of the week and move them to a sunny location during the last half of the week. Allow the plants to stay outdoors for increasingly longer periods of time each day. Always bring the leek plants indoors every night during the week of hardening.

Dig a shallow trench with the garden shovel in well-drained soil. Use the shovel as a guide for the width of the trench and only dig to a depth of 4 inches to 5 inches. Use the bulb planter to dig holes in the trench approximately four inches deep. Space the holes 6 inches apart. Space trenches approximately 1 foot to 2 feet apart, or a comfortable walking width.

Transplant the leek seedlings into the prepared holes when the seedlings are 6 inches to 12 inches in height. Carefully spread the roots out and fill in around the seedlings with soil, but only in the holes dug with the bulb planter.

Water the leek seedlings and continue to keep moist during the first week after transplanting. As the seedlings start to grow and develop new leaves, gradually fill in the trench with garden soil 1 inch at a time. Make certain to place the soil around the stalk of each leek plant when filling the trench.

Continue filling in the trench with soil every week, or as the leek plants show signs of growing taller. The goal is to develop the longest white stalks on the leek transplants. To achieve this goal, cover the stems with soil. When the trench becomes full of soil, continue to slightly mound soil around the leek plant as it grows taller. This additional soil prevents light from reaching the stems to develop additional leaves, instead of the desired white stalk.