Years ago, Grunder Landscaping Co. frequently had a surplus of plants and materials at their shop waiting to be used on jobs. Materials may or may not have been allocated to a specific job, it was pretty common for the plant procurement team to just buy a few extras when they found great quality or a great price and then work them into plans later.
Long story short, they got burned in 2008. They now only order materials once a job is sold and scheduled to reduce the cash they have tied up in inventory. They try to time their orders so that plant materials don't sit in their yard for more than a week or two to reduce the labor needed to keep everything alive and organized.