Gardening in Oregon can present special challenges, such as fog and heavy rains in some regions. Leeks, or allium porrum as they are known in Latin, grow best in cool climates with rich soil and some sun exposure. You can enhance leek growth by choosing a protected area in your garden, such as a south facing wall. Although you can certainly sow seed directly in the ground in Oregon, following the transplanting method protects young plants.
Spread 1 inch of potting soil in the tray. Moisten the soil. Plant leek seeds a quarter inch deep, with at least a quarter inch between each seed. Keep soil well moistened for eight to 10 days, until they sprout and have begun to grow.
Fill flowerpots with potting soil. Moisten the soil, then gently pull the sprouted leeks from the planting tray and plant in the flowerpots. Water regularly and feed with blood meal when plantings are a month old.
Start exposing your growing leeks to the outdoors eight to 10 weeks after sowing. Leave them outside during the day, bringing them in at night. Do this for two or three weeks.
Prepare the selected plot in your garden by mixing the soil with plenty of humus. When your leeks are about 10 to 12 weeks old, hoe out a 6-inch trench. Leave 2 feet between rows if using more than a row.
Transplant the largest leeks by pulling them out of the flowerpots gently and laying them standing with the roots down in the trench. Leave 3 to 4 inches between each plant. Spread a little humus directly on the roots, and then fill in the trench with the hoed out dirt.
Water the transplanted leeks well for two weeks. As they grow, you will need to add more soil around each plant, a process called hilling. Hilling ensures that the stalk stays white. Besides hilling and watering if dry, leeks need little attention until harvest.