How to Know When to Pick Lettuce as a Head

I know little about both gardening and plants. What I do know I have learned from books, from experience, and from mistakes. That knowledge hasn’t covered most the signs of maturity among my plants; some were obvious, such as the wax bean. The intricacies of lettuce have been harder to learn than it has been to grow.

Anyone can grow lettuce. Throw out some seeds, lightly water at dawn and dusk, wait two or three weeks, and presto! you have baby lettuce. But, now what? Like many, I harvested individual leaves early, before the lettuce qualified as a “head”. This leaf lettuce only amounted to a single serving at first picking, but that picking stimulated rapid growth. For the past month I’ve had nice heads of lettuce in my garden that provide biweekly salads.

Yet, last week I noticed that my lettuce aged almost over night. I looked a little closer and found the signs that I’d missed, so that I will harvest my heads in time from now on.

Maybe one day I won’t commit these mistakes as frequently.

Several signs of mature lettuce:

  • Leaf Shape
    Mature lettuce has a broad, curly leaf; immature lettuce is spoon-like with a long, narrow stalk.
  • Leaf Waviness
    Lettuce, when mature, has a wave to the leaves—the deeper the folds, the older the plant.
  • Leaf Color (Romaine Lettuces, etc)
    Romaine lettuce begins its life as a normal green plant that slowly, or quickly depending on the variety, changes to a brown color in its leaves. The De Morges Braun leaves gain a uniform brown hue when mature, and the end of the leaf turns a pink-rust color when old.
  • Texture
    I discovered that young lettuce feels particularly soft. This softness only departs when the lettuce becomes old and firm, when its leaves will tear apart with more easily.

I pick my De Morges Braun lettuce by the head when it reaches equilibrium in color. When the leaves are uniformly brown in color I sever the stem and refrigerate it that day, even when I have used that head as leaf lettuce. I find it unique that this variety grows old from the center out, and adorns its leaf tips with a rust-pink color.

I pick my “normal” lettuce, the Black-seeded Simpson, when its leaves curl and develop small spines on their back, but before their shade of green changes. When old, Black-seeded Simpson will change hue in one of two ways: its leaves may become pale yellow at the tips; or its leaves may become a darker green.

Now I have a mixture of just-right and too-old lettuces to eat—all at once.  At least we enjoy salads!

Leave a Comment