Butter Lettuce Planting Time. Lettuce (scientific name lactuca sativa) is quick to plant, and simple to harvest. The spacing of looseleaf lettuce depends on how you will harvest it.
If you plan on taking the outer leaves off and leaving the plant to grow, then spacing them is less of an issue. Once the leaves reach at least 2 inches (5.1 cm), you can start harvesting your butter lettuce at any time! From the time of planting, butter lettuce takes approximately 60 to 70 days to mature.
The spacing of looseleaf lettuce depends on how you will harvest it.
They act as “barrier plants” for the lettuce. Romaine and butterhead lettuce can be harvested in about 60 to 70 days from planting. (24 c.) and will bolt in hot weather. As the lettuce continues to grow,.