whats happening to my leaves

[Smeg]

42790hi all , and happy crimbo

it started about a week ago , i noticed 1 or 2 light coloured leaves, but with each day there's more and more . the only thing Ive changed lately is I've started to add my boost . I'm now 55 days into flowering , there nearly ready , I'm thinking about a week more , but this leave think is worrying me
its my first grow , and maybe this is normal when i think about , most trees dump there leaves i know ,
i took a pic
any ideas guys ??
thanks Smeg

(p.s thanks to forum for suggesting Picasa... what a cool little program )

[headband]

leaves turn yellow normally at the end of flowering when the plant puts all its energy to finish off flowering. The leaves will start to die off.

[Wise Man]

Yeah thats normal,dont worry.

Hope you have a nice harvest!