Pullet is the term for a young hen from the time she starts to lay eggs to her first seasonal moult. Hens generally start laying eggs at about 18 to 20 weeks of age. Egg production will slow down or stop (depending on the breed of hen) after the first moult which starts as winter approaches. Some breeds will lay eggs for up to ten years but no hen lays as many eggs per year as she does in that first super-productive season. In fact most hens start to eat more than the eggs they lay are worth by their third or fourth year. Kind hearted hobby hen keepers will ignore this disastrous state of affairs but the serious smallholder will not have that luxury. Butchering hens is part and parcel of hen keeping. Hens past their laying prime are the traditional ingredient of peasant style chicken soups.

 my chickens are 22 weeks old when will they start to lay eggs

 Hens will also continue to lay longer if their eggs are collected daily, if eggs are left in a nest the hens may get 'broody' stop laying and try to hatch. I'm from north central Texas, and My Orpington hens layed all year round.