It is best to install most hardscape areas before the irrigation system and plants. (Although top dressing is considered a hardscape element, it is usually installed after the plants.) As a last check prior to installation, measure and mark off hardscape areas. Temporary marking paint and marker flags are two tools that can be used to mark landscape components. Both can be purchased from local landscape and irrigation suppliers.
If irrigation lines run beneath fences, walls and other hardscape areas, it is a good idea to install a sleeve
under those spots. Mark and install sleeves for irrigation lines and outdoor lighting now.
If possible, purchase the entire quantity of each type of hardscape material at the same time. This will help to ensure color consistency, as colors in natural materials may vary somewhat, and will save time during the installation process.