The short answer for a Plymouth Rock chick
A young Plymouth Rock stays with its mother for about six to seven weeks before it is ready to be rehomed. Plymouth Rocks sit in the middle of the heritage-breed pace chart — their chicks feather steadily, neither racing like Leghorns nor dawdling like Orpingtons — and a broody Rock hen is a dependable, businesslike mother who wraps up her duties at around six weeks.
A steady breed's nursery pattern
A Plymouth Rock hen raises her chicks with a calm routine that makes the stages easy to read. For the first three weeks the chicks divide their time between foraging at her feet and warming underneath her, since their down insulates poorly and their early feathers are still arriving in bands across the shoulders and wings. In the sixth week the night-time arrangement changes visibly: the chicks take their own stretch of perch and the hen settles separately, and a keeper who checks the coop after dark can watch the rehoming date announce itself.
Readiness, checked bird by bird
A young Plymouth Rock is ready to rehome when its feathering closes completely over the back and breast and the last down has gone from under the wings, so that rain and a cool night hold no threat for it in an outdoor pen. It should be feeding and drinking with no guidance from the hen, scratching and foraging actively, and feeling solid and well-covered across the breastbone when you lift it. Barred Plymouth Rocks offer a small bonus at this stage: their plumage pattern is developed enough that the lighter cockerels and darker pullets can usually be told apart, so a keeper rehoming youngsters can describe each bird's likely sex honestly rather than vaguely.
The move itself
Rehome a young Plymouth Rock the low-drama way: lift the youngsters off the perch after dark, when they are drowsy and handle without a chase, and travel them in a ventilated box on non-slip bedding in the company of their brood-mates. Send a bag of their current feed with them, because a Plymouth Rock chick that lands on unfamiliar feed in an unfamiliar pen often eats too little for the first crucial day or two. Prepare the new keeper for the breed's nature — these are calm, ground-focused birds that settle well but should be introduced to any existing youngsters of a similar age rather than dropped in with adult hens who will rank them harshly.
Timing mistakes with this breed
The Plymouth Rock's steadiness creates its own trap: because nothing goes dramatically wrong early, keepers rehome at five weeks on the strength of good shoulder feathering and miss the down still hiding under the wings, and the chicks meet their first cold rain in the new pen underdressed. Sending one chick alone — often the friendliest, because it is easiest to catch and carry — condemns the most social bird to the loneliest arrival, and Plymouth Rocks rehomed singly commonly pine and lose condition. Selling youngsters as definite pullets before the barring and combs have had their say is the final quiet error; at six weeks the evidence is good but not absolute, and honest wording at handover protects everyone.
What the new keeper should receive
A young Plymouth Rock arrives best with its facts in front of it: hatch date, whether it was hen-raised the whole way, the feed it is on, its likely sex and the signs that suggest it, and any individual notes from the nursery weeks — a chick that was slow to feather, one that was treated for a pasted vent as a day-old. A rehomed youngster that stops eating, hunches apart from its new companions, or breathes with difficulty should be seen by a veterinarian promptly, and that conversation starts with exactly the details a good handover passes on. Transferring a Plymouth Rock's record through KinsLe's Transferrable Profiles means those hatch, feed, and feathering notes reach the new keeper as a living profile the bird keeps, rather than a verbal summary that fades within the week.