Grow Lettuce from Seed Fine Gardening This is how I grow lettuce from seed. I begin starting lettuce seeds in March and plant out in the garden in April. In about 60 days, theyre ready to harvest. If you are interested in saving seed, When to Plant Flowers: Perennial, Annual, and Bulb Planting Guide The Old Farmer's Almanac How to Care for Firestick Succulents Dengarden As Ye Sow: Saving and Planting Poppy Seeds Flower Magazine Backyard growing New Zealand Avocado