How long does lettuce last in the fridge?

The realistic range: a whole, unwashed head of iceberg lettuce holds up for one to two weeks in the fridge, romaine and other sturdier heads for about a week to ten days, and soft-leaf varieties like butter or bibb lettuce for closer to three to five days. Pre-washed bagged salad is the odd one out — treat it as good for a few days once opened, whatever the printed date on the bag implies. None of those numbers move much once the leaf has actually been cut or torn; that is where the clock changes completely.

Why lettuce behaves nothing like a carrot

A lettuce leaf is built almost entirely from large, thin-walled cells packed with water — roughly ninety-five percent of its weight is water held inside a structure with very little rigidity of its own. Cut, tear, or bruise those cells and they rupture, spilling their contents and exposing them to air in a way an intact leaf never is. The browning that shows up at a torn edge within an hour is the same basic chemistry as a cut apple going brown: an enzyme called polyphenol oxidase reacting with oxygen the moment the cell wall breaks. It is not spoilage and not a safety problem, just fast, visible oxidation — which is also why a whole, uncut head keeps so much longer than the same lettuce already chopped into a bowl. The intact skin is doing almost all of the protective work.

The fruit next to it in the crisper drawer is working against it

Lettuce is unusually sensitive to ethylene, the ripening gas that apples, bananas, tomatoes, and pears all give off as they age. On most produce ethylene speeds up ripening. On lettuce it does something worse: it triggers a russet-brown, freckled spotting on the leaves that has nothing to do with age or bruising, just proximity. A head of lettuce sitting for a few days next to a bowl of apples or a bag of ripening tomatoes can pick up spotting through the bag before it has done anything else wrong. This is one of the most common invisible causes of a lettuce that "went bad early" for no obvious reason — it was never given a fair chance. Keeping ethylene-producing fruit in a separate drawer, or at least not stacked directly against leafy vegetables, is a small habit with an outsized effect here.

What actually decides the window for a given head

Density matters more than the variety name. Iceberg's tightly packed, low-surface-area head is what makes it the most forgiving lettuce in the fridge, not anything special about the plant itself — there is simply less exposed leaf edge for water to escape from and less surface for damage to spread across. Loose-leaf and butter lettuces are built the opposite way, with soft, open leaves that lose moisture fast and bruise if a shopping bag so much as leans on them, which is why they sit at the shorter end of the range even bought the same day.

Moisture has to be balanced, not maximised. Too little humidity and the leaves wilt as they lose water to the dry air a fridge constantly circulates. Too much, especially trapped inside a sealed bag with no airflow, and the same moisture that would have prevented wilting instead turns the leaf slimy as bacteria take advantage of it. The fix for both problems is the same one produce sections have relied on for decades: wrap the head loosely in a dry paper towel before bagging it. The towel absorbs the excess moisture that would otherwise pool against the leaf, while the loose bag still holds enough humidity to stop it drying out — and swapping a soaked towel for a dry one partway through the week genuinely extends things further.

Whole beats washed, and washed beats cut. Pre-washed bagged salad greens have already had their protective outer leaves removed and their surface cells disturbed by the washing and spinning process at the factory, which is exactly why a bag's real window is days, not the week or more a whole head manages, whatever the "best by" date printed on the film suggests. If you do wash lettuce ahead of time at home, drying it completely — a salad spinner, not just a shake — matters more than almost any other single step, for the same reason drying berries before storing them does: a wet leaf in a closed container is doing the bacteria's work for it.

Wilted is not the same problem as slimy

These two failures look similar from across the kitchen but mean opposite things. A wilted leaf has simply lost water it can, in many cases, get back — soaking limp lettuce in a bowl of ice water for ten to twenty minutes lets the cells reabsorb some of what they lost, and it is a genuinely effective trick, not folklore, because the underlying cell structure is usually still intact. A slimy leaf is a different situation entirely: the cell walls themselves have broken down, most often from bacterial activity in trapped moisture, and that texture does not reverse with a soak. Slime, a sour smell, or a distinctly darkened, translucent patch are the signs worth trusting over wilting, which on its own is just dehydration and rarely a reason to throw the rest of the head away.

What actually helps

• Buy whole, cut later. A head lasts noticeably longer than the same lettuce pre-chopped, because the intact leaf is doing real protective work that a cut edge cannot.
• Keep it away from apples, bananas, and ripening tomatoes. Ethylene causes the brown speckling people usually blame on age.
• Wrap loose in a dry paper towel, not sealed airtight. The towel manages the moisture that either dries the leaf out or turns it slimy, depending on which way the balance tips.
• Dry it completely if you do wash ahead. A damp leaf in a closed bag is the fastest route to slime, regardless of how sturdy the variety is.
• Try ice water before giving up on a wilted head. It is a real fix for dehydration, not for the slime that means the leaf is actually done.

Lettuce is also one of the easiest things to lose track of precisely because a whole head looks fine from the outside right up until it does not — there is no obvious skin change the way an aging avocado has, and by the time a bag of greens shows through the crisper drawer, a rotation has usually already happened underneath it. Munch logs each batch with the day it went in and where it is stored, shared with everyone in the household, so a head of lettuce with a few days left shows up on the same list as everything else, instead of relying on whoever put it away remembering it is still there.