Vegetables GardeningGrow Leek American Flag Seed-starting 4: Growing leek and onion seedlings By Sumit - February 22, 2015 0 1228 Share on Facebook Tweet on Twitter Learn how to encourage your leek and onion seedlings to develop a strong root system once they’re up and growing. This video also covers how to feed and water any type of seedling. 0.00 avg. rating (0% score) - 0 votes