By Bonnie L. Grant
Container growing lettuce is a common practice for small space gardeners such as apartment dwellers. It can allow an early start because the pots are brought indoors during light freezes and left outdoors during early spring days. Lettuce is a cool season crop and leaves develop best in cool but not chill temperatures. Growing lettuce in containers also allows you to control weeds and pests more easily than in a large gardening space and affords quick access when you want some leaves for a salad.
Planting Lettuce in Container
Growing lettuce in containers requires the right type of pot and planting medium. Lettuce needs ample room for roots but you can grow several varieties in 6 to 12 inch pots. The greens need a consistent supply of moisture as they are almost 95 percent water but cannot tolerate wet roots. A clay pot provides a permeable surface that can evaporate any excess water and prevent soggy roots. Make sure there are adequate drainage holes in whatever container you chose.
The physical attributes for how to grow lettuce in a container are just the media and pots but now we must turn our attention to sowing and management. Planting lettuce in container gardens can be done by direct sowing or transplants. Prior to planting add ½ tablespoon of time release fertilizer per gallon of soil. Transplants should be buried ¼ inch deeper than they would be in garden soil and set 6 to 12 inches apart. Seeds are sown when soils are not frozen, ½ inch deep and 4 to 12 inches apart. Leaf lettuces can be closer together than head types.
How to Grow Lettuce in a Container
Use a professional soil mix for planting lettuce in container situations, as it is formulated to hold water and provide nutrients. A soil mix is usually peat or compost, soil, vermiculite or perlite for water retention and often manure. You will need 1 to 3 ½ gallons of soil depending on the size of your container. Choose a lettuce mix that is “cut and come again” for repeat harvests. Some recommended varieties for growing lettuce in pots are Black Seeded Thompson and red or green oak leaf types. Loose leaf lettuces are better suited to pots than head lettuce.
The most important resource to provide when growing lettuce in containers is water. Lettuce has shallow roots and responds best to consistent shallow watering. Plants grown in the garden need at least an inch per week so factoring in evaporation, lettuce in pots will need a bit more. There are numerous pest that enjoy lettuce as much as you do. Combat them with blasts of water, insecticidal soap and for slugs, containers of beer.
Harvesting Container Growing Lettuce
Cut the outside leaves of loose lettuce when they are young. The leaves will grow back and then you can cut away the entire plant. Always cut lettuce when it is young and tender as they are quick to bolt and become bitter.