My plant is woody and hairy?

So I have two plants less than a month old. One is flimsy, very green and vibrant, and is growing rather fast. The other is short, bushy, and dark green. It has an almost woody stem. It is more hairy as well, and smells more citrus like. I am pretty sure they are both the same strain of Indica, same smell and leave size/shape. I also got the seeds from the same bag. If anyone knows why the hell this thing is turning into a Christmas tree then please tell. Thanks and happy!