I always wash mine as soon as they are finished. But I will say that if you have a new washing machine that is HE and self-filling, make sure you use a setting that will allow more water in the tub. I always use the bulky/bedding setting because it adds considerably more water to the tub. My mom didn't do that with the quilt she made me, and I'm pretty sure that's why red dye deposited on some spots and stained the quilt. :-(