How Deep of a Container for Lettuce Growing?

Container Depth

• Lettuce does best in broad, shallow containers, making it easy to grow in a variety of containers. Because they are shallow-root crops, they do not require very deep containers in which to grow. Ideally, containers 6 to 10 inches deep should be sufficient for lettuce to establish firm roots and grow well. You can use deep containers, but the added depth may be unnecessary. You can try shallower containers, but they may stunt the growth of the plant.

Types of Containers

• The two main types of containers are porous and nonporous. Clay is the most common type of porous container. Plastic, metal and glass are examples of nonporous containers. Wood, often lined with plastic, is an example of a popular semiporous container. All types of containers come in a variety of shapes and sizes and vary in weight, cost, heat retention and watering requirements. All containers, however, must have proper drainage to be suitable for growing lettuce.

Potting Mixes

• The soil or mix in which the lettuce grows must provide adequate moisture and nutrients for the plant to thrive. It is advisable to use a soil mix or soilless mix, rather than pure garden soil, because they tend to be lighter, better aerated and more balanced in nutrients. Most garden stores have a variety of choices.

Caring for the Lettuce

• Lettuces that grow in containers require frequent watering. It is important to check the soil or mixture regularly to ensure it is moist, but not too wet. If it becomes too dry, the plant's energy becomes focused on growing roots, not leaves. If it is too wet, the nutrients can wash out of the bottom of the container. Lettuce in containers is fairly tolerant to cooler temperatures, but does require moderate to full sun.