Days to Maturity
Every seed packet will have a ‘days to maturity’ section. It will provide you with the number of days between planting and harvest. Typically Romaine varieties take between 50-85 days to mature. This number is derived from multiple field tests on that specific variety so it’s a great estimate. It’s not an exactly accurate timetable though.
Conditions in your garden may be vastly different from those in the field. Nutrient and water regiments are different, sunlight is different, pest damage can set plants back. So, it’s important to learn how to look at your plants and determine if they are ready to cut.
Time of Day
To get the most from your lettuce plants harvest them at the right time of day. If harvested during a harsh sun, lettuce tends to wilt within hours. It’s fine if you are eating it right away. However, if you want to store the head for any number of days you must harvest early in the morning.
Farmers harvest lettuce between 2 o’clock in the morning and just before sunrise. Get to them before the dew evaporates for the longest shelf life possible. It’s a job that few gardeners look forward too, but it’s one that pays in fresh crisp heads of Romaine lettuce. To determine if a head is mature enough to harvest, there are three tests that home gardeners can do:
- The Squeeze Test
- Base Size Test
- The Snap Test
A squeeze test in an easy way to determine if a Romaine head is mature enough to harvest. The heads should be firm and compact, not airy or limp. Give the head a light squeeze with your fingers. Feel for fullness, it shouldn’t collapse but remain solid. There should be some bounce-back indicating that it is full of moisture and not dry.
Base Size Test
Typically the base of a mature Romaine stem should be about 3 inches in diameter. This is for full-sized Romaine, baby Romaine varieties will be smaller at the base. You may also have mature heads with smaller stems if they grew close together or did not get the maximum amount of sunlight. If a stem is small, but the head passes the squeeze test it is likely ready to harvest.
The leaves of a mature Romaine lettuce plant should be crisp and crunchy. Take an outer leaf of one of your plants and hold it toward the base at the thick white stem. Break it off and if it snaps with a crispiness then the plant is ready to harvest. If it bends and is pliable, the plant is still immature.