Soil rich with organic matter and chunky grit such as sharp gravel or horticultural sand is the optimum outdoor planting medium because immature clematis roots find it easier to reach out and grow. Whereas dense soils like clay or rocky soils don’t allow the roots much space to take hold. Native soil that is sandy, as well as clay based soils that are amended, are perfect for growing clematis.
For garden soil that is less than optimum, amend your soil to create a better planting medium.
Clematis tolerate a range of Ph and are quite adaptable to a variety of soil types.
For planting outdoors, amendments for your native soil include: proprietary bagged compost for flower gardens, leaf-mould, decomposed grass clippings, sharp gravel or sand, oyster shell ( sold at feed stores as poultry grit in many areas), composed pine fines or mushroom compost.
For planting in containers, amendments for traditional bagged ‘potting soil’ include composted pine fines, oyster shell, extra perlite, and bagged compost for flower gardens. Alternate bullet point, For planting in containers, use a proprietary bagged planting mix that lists Canadian peat as the first ingredient.
Learn about fertilizing your clematis