Rhododendron Mix is a mixture of Fir Bark, Red Lava, and Nursery Mix. Amend your planting hole with equal parts native soil and Rhododendron Mix. For areas with heavy clay soil plant the Rhododendons a little higher than the grade. This will provide better drainage and aeration. We sell the Rhododendron Mix in one cubic foot bags, we supply the bags, you fill them. For larger areas you will want to purchase the Rhododendron Mix by the cubic yard. We can load your truck or for a fee you can rent our dump truck or have us deliver to your home or job site.