Should the coop light come on in the morning or the evening?

The morning, and this matters more than it sounds. If you extend the day at the evening end, the light switches off instantly and the birds are caught on the floor in sudden total darkness — chickens have very poor night vision and need dusk to find their way onto the roost. Adding the hours before sunrise instead means the artificial light gives way to natural daylight, and the birds still get a real dusk to roost by. If you must add light in the evening, it needs a dimmer that fades out over several minutes.

Does adding light in winter shorten a hen's laying life?

This is the most-argued point in backyard chicken keeping, and the honest answer is that the extension publications do not support the strong version of the claim. They present winter lighting as ordinary flock management, with no warning that it exhausts a hen early. What is true is that a hen has a finite number of ova and that light increases how quickly she works through them, so a lit flock lays more eggs sooner. Whether that shortens her productive years or simply rearranges them is not something we can cite a source for either way — so we do not claim it in either direction.

Should I light the coop while my hens are molting?

It will not help. Light addresses day length; a molt is feather replacement, and the hen has stopped laying because she is putting protein into feathers rather than eggs. Adding light to a molting bird does not shorten the molt. The sensible sequence is to let the molting birds finish and use light to hold the rest of the flock in lay — and to make sure the molting birds have the protein they need while they re-feather.

Should I Put a Light in My Coop in Winter?

It genuinely works — hens lay on day length, not temperature, so adding hours brings the eggs back. It is also entirely optional, and there are three ways to get it wrong.

Figures reviewed against university extension guidance · Last reviewed August 2026

Why winter stops the eggs

A hen's laying cycle is triggered by day length, not temperature. Light entering the eye drives the hormonal cascade that releases a yolk, so as autumn days shorten, laying tapers and then stops. Cold has very little to do with it — which is why a heated coop does not produce winter eggs and an extra hour of light does.

The two extension services that publish numbers give them from opposite directions, and both are useful. Penn State: "For mature laying hens, aim for 16 hours of light per day." University of Arizona approaches it as a trigger — hens need about 14 hours to hold peak production, and light should be "resumed when natural daylight falls below 14 hours."

So 14 hours is when to start and 16 hours is what to aim at. They are not two estimates of the same thing to be averaged into 15.

The three ways to get it wrong

1. Lighting the evening instead of the morning

This is the mistake that actually harms birds, and it is the most common one. If you extend the day at the evening end, the timer clicks off and the coop goes from lit to pitch black instantly. Chickens have very poor night vision and rely on gradual dusk to find their way up onto the roost. Cut the light abruptly and you leave birds stranded on the floor in the dark, where they will spend the night huddled in a corner or in the nest boxes.

Add the hours before sunrise instead. The artificial light hands over to natural daylight, the birds get a real sunset to roost by, and nothing about their evening changes. If you have no choice but to light the evening, it needs a dimmer that fades out over several minutes.

2. Switching it off abruptly in spring

Penn State is blunt about this one: "Never decrease the lighting period on birds in production, or they will stop laying." Pulling the plug in March produces exactly the laying stop you installed the light to avoid.

Taper instead. As natural daylight lengthens, reduce the supplemental hours to match, so thetotal day the birds experience never actually gets shorter. The same rule applies on the way up: ramp by no more than about 1 hour per week.

3. Installing far too much light

The threshold for stimulating laying is around 0.5 foot-candles at bird height — bright enough to read a newspaper by, and no more. Penn State cautions against oversized bulbs, recommending no more than about 40 watts incandescent in a small coop. A single 9W LED covers a backyard coop comfortably.

Flooding a coop wastes power, and in a confined winter coop bright light can encourage pecking. Our coop lighting calculator works out the switch-on time for your latitude and date, so you are not guessing at how many hours the natural day is actually giving you.

The argument against, taken seriously

Plenty of experienced keepers deliberately do not light their coops, and the reasoning deserves a fair hearing rather than a dismissal.

The case is that a hen is hatched with a finite supply of ova, that winter is a natural rest, and that pushing her to lay through it uses her up faster. The counter-case is that the extension publications treat winter lighting as ordinary flock management and none of them warns that it exhausts a hen early.

We are not going to resolve that here, and we are not going to pretend it is settled. What is well supported is that a lit flock lays more eggs sooner. Whether that shortens a hen's productive years or simply moves the eggs forward is not something we found a source for in either direction — so we do not claim it in either direction. If you keep hens as pets you expect to live for years, "no light" is a perfectly defensible choice. If you keep them for eggs, so is lighting them.

When to skip it entirely

Pullets in their first winter. A spring-hatched pullet will usually lay through her first winter without help, because she has not molted yet.
Birds mid-molt. Light addresses day length, not feather growth. It will not shorten a molt — see chicken molting.
If you cannot run it reliably. An intermittent light is worse than none, because every failure is an abrupt decrease in day length.
If eggs are not the point. A pet flock loses nothing by resting.

A worked example

Six two-year-old hens in Ohio, done molting by early November. Natural daylight in mid-November is around 10 hours and falling; sunrise is about 7:15am.

Daylight is already below the 14-hour trigger, so lighting is worthwhile. To reach 16 hours from 10 means adding 6 — but not at once. Ramp at 1 hour a week: start with the timer at 6:15am in week one, 5:15am in week two, and so on until it comes on at about 1:15am… which is the point at which you notice that 16 hours in deep midwinter is a lot to ask, and settle for holding 14.

A 9W LED on a timer, mounted so it is not glaring straight at the roost. Morning only; natural dusk left alone. In February, as sunrise creeps earlier, the timer creeps back with it so the total day never shrinks. Eggs through winter, no abrupt darkness, nothing switched off suddenly.

Sources

The hour targets, the ramp rate, the intensity threshold and the wattage ceiling are all quoted figures from Penn State and University of Arizona Extension. The question of whether lighting shortens a hen's productive life is treated as unresolved on purpose — no source we could find supports the strong claim in either direction, and this page says so rather than picking a side.

Penn State Extension — Artificial Lighting for Winter Egg Production
University of Arizona Cooperative Extension — Lighting Schedules for Arizona Backyard Laying Flocks
Penn State Extension — Management Requirements for Laying Flocks
Virginia Cooperative Extension — Why Have My Hens Stopped Laying? 5 Factors that Impact Egg Production (2902-1097)
University of Minnesota Extension — Raising Chickens for Eggs
University of Florida IFAS Extension — Factors Affecting Egg Production in Backyard Chicken Flocks (PS029)

Frequently asked questions

How many hours of light do chickens need to lay in winter?: Penn State Extension says "for mature laying hens, aim for 16 hours of light per day." University of Arizona Extension gives the trigger from the other direction — hens need about 14 hours to maintain peak production, and supplemental light should be "resumed when natural daylight falls below 14 hours." So 14 hours is the threshold at which adding light starts to matter and 16 hours is the target to aim for. Those are two different figures doing two different jobs, and averaging them into a single number loses the distinction.
Should the coop light come on in the morning or the evening?: The morning, and this matters more than it sounds. If you extend the day at the evening end, the light switches off instantly and the birds are caught on the floor in sudden total darkness — chickens have very poor night vision and need dusk to find their way onto the roost. Adding the hours before sunrise instead means the artificial light gives way to natural daylight, and the birds still get a real dusk to roost by. If you must add light in the evening, it needs a dimmer that fades out over several minutes.
Does adding light in winter shorten a hen's laying life?: This is the most-argued point in backyard chicken keeping, and the honest answer is that the extension publications do not support the strong version of the claim. They present winter lighting as ordinary flock management, with no warning that it exhausts a hen early. What is true is that a hen has a finite number of ova and that light increases how quickly she works through them, so a lit flock lays more eggs sooner. Whether that shortens her productive years or simply rearranges them is not something we can cite a source for either way — so we do not claim it in either direction.
How bright does a coop light need to be?: Much dimmer than most people install. The working threshold for stimulating laying is around 0.5 foot-candles at bird height — enough to read a newspaper by, not enough to floodlight a coop. Penn State cautions against oversized bulbs, recommending you only use bulbs up to about 40 watts incandescent in a small coop. A single 9-watt LED covers a backyard coop comfortably. Brighter is not better; it wastes power and can encourage pecking.
When should I start and stop supplemental lighting?: Start in autumn as natural daylight approaches 14 hours, rather than waiting for the shortest days, and ramp up gradually — no more than about one extra hour per week. Stopping is where people go wrong. Penn State is blunt: "Never decrease the lighting period on birds in production, or they will stop laying." Cutting the light abruptly in spring produces exactly the laying stop you added it to avoid. Taper it off as natural daylight rises to meet it, so the total day length never actually falls.
Should I light the coop while my hens are molting?: It will not help. Light addresses day length; a molt is feather replacement, and the hen has stopped laying because she is putting protein into feathers rather than eggs. Adding light to a molting bird does not shorten the molt. The sensible sequence is to let the molting birds finish and use light to hold the rest of the flock in lay — and to make sure the molting birds have the protein they need while they re-feather.