Originally Posted by seoulfully
depends on what you want. if you have raw denim (this applies a little less to washed), then a lot of ppl go 6 months or more before the first wash. then as long as they can between washes. maybe every 3-4 months. of course this is if you want a certain look (faded, whiskers, honeycombs, etc). lately i think more and more that ppl are all doing the same thing and while everyone gets their own fades and whiskers, i think it's all kind of the same look and ppl are too religious about it. so do what you want with your clothes. i'd still suggest not washing denim all that often just so you don't weaken the fabric too much (well more about the dryer than the washer, but still).
Actually both Brian and I would recommend washing at least once a month (then hang or flat dry) if you want the maximum durability. Wearing jeans for prolonged periods of time without washing actually decrease their lifetime, for 2 reasons.
1) Bacteria love to eat organic matter (which your jeans are) and
2) Washing allows the denim to shrink back close to its original size, allowing the yarn to regain elasticity and restrengthening the weave. Wearing a pair of jeans for prolonged period without washing stretches the jeans out (as we all know) and weakens the weave.
I like some whiskering in my jeans, but I think that excessive whiskering without corresponding fading (which comes from washing) looks pretty contrived...