Romaine lettuce can be regrown in water from its base, providing a temporary second harvest from a kitchen scrap. This experiment yields a small quantity of fresh leaves without needing soil or a full garden setup. While it will not produce a full head of lettuce, the process is simple and fast, providing inner leaves ready for harvest in about two weeks.
Why Romaine Lettuce Regrows
Romaine regrows because the remaining stalk section contains the plant’s growth center. This central area, known as meristematic tissue, is responsible for cell division and producing new leaves and roots. When the leaves are cut, this tissue remains intact at the core of the base. Placing the base in water hydrates and reactivates this dormant growth center. The meristematic tissue develops new, smaller leaves from the top and simultaneously initiates new roots from the bottom. Since water provides no nutrients, the new growth relies on limited stored energy reserves within the base.
The Step-by-Step Regrowing Process
To begin regrowing romaine, ensure the base is approximately one to two inches high after removing the outer leaves. Use a sharp knife to make a clean, straight cut across the bottom of the stalk to expose fresh tissue. Select a small container, such as a shallow dish or mug, wide enough to hold the base upright. Fill the container with clean water so that only the bottom half-inch to one inch of the base is submerged. The water level must be shallow enough to hydrate the bottom while keeping the upper core dry to prevent rot. Place the container in a location that receives bright, indirect sunlight, such as a windowsill. Within two to three days, small shoots should form at the center, and tiny roots should extend from the bottom.
Maintaining Your Regrown Lettuce and When to Harvest
Ongoing Care
Ongoing care is necessary to keep the romaine base healthy and prevent sliminess or mold. Change the water in the container every one to two days to ensure the base sits in fresh, oxygenated water. Stagnant water encourages bacterial growth, causing the base to become brown and mushy.
Harvesting the Leaves
The new leaves grow rapidly, often reaching a harvestable size of two to four inches within 10 to 14 days. This regrowth is a second harvest and yields only a small cluster of leaves, not a dense head of lettuce. Harvest the leaves by cutting the new growth near the original stump once they are large enough or when the growth rate slows. Delaying the harvest can cause the lettuce to “bolt,” meaning the plant focuses energy on producing a seed stalk, which results in bitter leaves.
When to Discard the Base
After one or two small harvests, the base will have depleted its internal energy stores. At this point, the base should be discarded. You can then start a new base using a fresh stump.