Lettuce
Question from Christine:
I started lettuce seeds in September (Romaine, Butter Crunch, Black Seeded Simpson) and transplanted them into a 16″ raised bed with new topsoil and timed release fertilizer with liquid humic acid as a transplant drench. I recently applied some Dr. Earth liquid all purpose fertilizer and they are now under 55% shade cloth to keep those voracious cabbage moth caterpillars and loopers under control. They’re growing beautifully and I’ve been harvesting outside leaves, but they’re just not crunchy. I’ve tried the ice water bath just after picking, harvesting only in the cool of the morning, and once tried refrigerating without washing until ready to use. I live in Carlsbad about 4-5 miles from the coast. Is there anything I can do to get the leaves crisper?
Answer from Pat:
In case you did not get my recent reply, here is another (and probably clearer) answer. Crisp lettuce results from variety, fast growth in cool weather, and method of harvesting. There are three methods of harvesting lettuce: (1.) Cut off and use the outer leaves. Continue to water and fertilize lettuce plants so the central head continues growing and producing outer leaves. This method gives you a long harvest but does not produce very crisp lettuce since young outer leaves are usually tender, not crisp. The second harvesting method is to use scissors to cut off all the leaves when the plants are young, like harvesting mesclun. Leave the roots in the ground. Continue watering and feeding and roots may produce a second and sometimes even a third crop. In this case the leaves will not be crisp because young, immature lettuce leaves are more delicate and tender than crisp. (Think of the mesclun you purchase in plastic bags or boxes in the grocery store. It’s more tender and delicate than crisp.) (3.) The third method is to harvest whole heads, then pull out and compost the roots. Amend the soil, fertilize and plant another crop where the head of lettuce formerly grew. This method will give you crisp heads, as you will see if you plant Romaine lettuce, care for it properly by watering and fertilizing enough so it grows rapidly in cool weather. Judging by my own experience, home-grown Romaine lettuce is every bit as good or better than any you can buy in the store and it is very crisp. It is the central head and ribs of Romaine lettuce that are the crisp part.
Other factors that influence crispness are picking early in the day, then rinsing, spinning, and chilling in plastic or cloth bags in the refrigerator before serving and also variety. Variety also matters! Read the descriptions in seed catalogues or packages or look up the descriptions of varieties online. Romaine is crisp when heads and are mature. (The juice-filled ribs of Romaine are the crisp part along with the crinkly blanched leaves inside, but not the outer deep-green leaves, which are usually more tough than tender on mature Romaine.) Butter Crunch has tender, buttery outer leaves and crunchy yellowish heads hidden inside. That’s why it’s called “Butter Crunch’.) ‘Black Seeded Simpson’ is prized for its tender leaves, not for crispness.