The hydroponic growing method is becoming increasingly more popular with urban gardeners, especially in cooler climates where the growing season is short. While hydroponic set ups can get quite elaborate and expensive, the fundamentals can easily be applied to a basic set up that only requires a mason jar, water, and sunlight.
To regrow your romaine lettuce, take the end nub of the plant and place it in 1/2 inches of water in a mason jar. Place the mason jar near direct access to sunlight such as a window sill or outside during the spring and summer months. Change the water every 2-3 days and keep a regular eye on the plant to make sure it doesn’t absorb all the water and is sitting dry in the mason jar.
The picture shown here is about after two weeks of growth. Regrowing romaine usually takes 2 – 3 months.