Hello. I am in zone 4 in southern Vermont, and I am seeking a lawn grass that wont spread itself into the bed over time. Something that does not send out creeping segments, that grows upright. I plan to mow it to about 4-6 inches deep (longer than typical lawns), and I am hoping there is something that wont lay over on itself. I can post examples of the current grass, and which ones I like, and which areas I dislike. I cannot identify grasses on my own, but there is one type in the existing lawn that seems nice. I do not mind an annual grass, so long as it is easy to grow every year. The lawn is compacted. I have dethatched it what I can by hand with a rake, but it is an older lawn, with big rocks throughout. The soil, where there is enough soil over the rocks (which I am slowly digging out one at a time, thus the bare patches), is nice soil, full of earthworms, and the same soil in the beds grows lilies, lily of the valley, rhododendrons, lilacs, and hydrangeas with no effort. This is for a north side of a 2 story building's lawn, so it is mostly shaded.