Westland Aftercut Ultra Green Lawn Feed and Iron Supplement. This product will green up your lawn in 3 days and help you with your moss problems. The product is ideal for amateur and experienced gardeners as there is no scorching risk due to its balanced ingredients. When using Ultra Green+ you will create a strong and healthy lawn that will crowd out moss and weeds. Black spots can appear temporary if your lawn has large amounts of moss, simply rake these out and overseed.