My barred rock hens have started to lay, but are laying everywhere except for the nesting boxes. Is this normal behaviour or is it something I should worry about
Yes, it is normal. Use straw and shavings in your nesting boxes. I add Curtains too make it more private for them....
This is a common experience - the reason(s) can vary and, thus, so can the ways to fix it. Can you post some photos of the interior of your coop so that we can see the nest boxes you have and how they relate to the rest of the coop? Often there are things about the boxes themselves or how they are located that make them unappealing to a bird looking to nest. Have you tried putting "bait" in the boxes to show them what the nest box is for? Using golf balls, wooden eggs, etc can help to demonstrate to a new layer that the nest box is a good place to go to lay her eggs. Are your birds free rangning during the day and, if so, are you finding eggs away from the coop itself or just in the coop but not in the nest boxes? If you find eggs scattered all over the yard, etc it can help to confine the flock for a few weeks once birds start to lay so that they get "homed" to the use of the coop and nest boxes as the place to go for their laying time vs. just hunkering down wherever they might be while out ranging.
