Using Gravel to Keep Weeds Down?

Being elderly, we are finding keeping on top of weeding flower beds is getting beyond us. We are wanting to cover a large raised bed with some sort of gravel, on top of weed control blanket, then we shall put some decorative shrubs in. Can anyone advise on whether we should use pea shingle or gravel. We are told that stone chippings will become covered in algae, hence a leaning to gravel. Any advice would be greatly appreciated.

By Ann Y