Types of Containers
Lettuce will grow in just about any container that has good drainage. Lettuce plants have relatively short roots; a container with a 6 to 12-inch depth will be fine. Terracotta pots tend to dry out faster than plastic pots. You may need to water them more often or line them with plastic before planting.
Pots with a 4 to 6-inch width can hold about 2 lettuce plants. Plants should be spaced at least 3 inches from each other. Increase the opening size in order to accommodate more plants with your spacing requirements in mind.
An all-purpose organic potting mix is a perfect lettuce medium. If you would like to get the most from your container garden, mix in 50% aged cow manure or finished compost. Vermiculite is another handy addition to a potting mix. It will retain moisture longer and help to prevent compaction. Since lettuce requires moisture at all times, vermiculite is a perfect amendment. Here is a recipe for an all-purpose homemade potting mixture:
- One part coir peat (you could also use rice hulls, decomposed wood chips, or leaf mold)
- One part asbestos-free vermiculite
- Two parts sieved compost
- Top off with worm castings
Fill your container so that the lip is above the soil about 1½ inch. Make sure the medium is moist, or soak it down a few minutes before seeding. Sprinkle lettuce seeds onto your soil generously; you will thin them out later. Cover the seed with ¼ inch of potting mix and water thoroughly. Keep your seedlings moist from then on. The watering schedule will depend on the retention of your potting mix.
Watering could need to be done every day, or if your potting mix retains a lot of moisture every three days. Check the surface of the soil daily. If it’s dry to the touch then water it. Be sure that your container drains excess water well to avoid waterlogged roots.
Some gardeners use the tray method to water lettuce. Place your pot into a tray of water deep enough so the soil wicks up the moisture, but not deep enough to drown the roots of your lettuce plants. This method can reduce labor and prevent certain molds from contaminating your plants.
Types of Lettuce
Most gardeners grow lose leaf lettuces when planting in containers. These types not only grow well packed together, they also provide a harvest within a couple of months and throughout the season. Pick the lower leaves as the plant grows, allowing new leaves to spring out from the center.