A hosta plant generally reaches full maturity in 4to8 years and its size depends on the species. Example: a 'Baby Bunting' grows 8 to 10in. in diameter. A 'Blue Angel' will get 8 feet in diameter.Hostas grow best in morning sun with afternoon shade. A rule of thumb,the darker bluish leaf variety needs more shade and the yellows and chartreuse leaf variety's can tolerate more sun. They like a rich moist soil and slightly acidic.Fertilize with a 10-10-10 or the best bang for the buck is Kmart's K-Gro water soluble. It has every trace element in it.