There are many plants that can grow well in the crevices of rock walls so be sure to weed out any tree seedlings or other volunteers that may settle in between rocks.
Growing plants on rock walls.
Hens and chicks are great plants for any rock garden because these small plants multiply as they grow and because of their size they are able to creep into the smallest spaces in the garden to make it fuller.
They do not need a lot of water to grow which makes them ideal for rocky soil that will not retain water.
Plants with a trailing habit such as ivy leaved toadflax are designed for cascading down rock faces or scree slopes and can thrive in a wall.
To tough forgiving annuals such as wallflowers erysimum cheiri trailing lobelia erinus and snapdragons antirrhinum majus that reseed themselves from year to.
It readily grows in nutrient poor soil as long as it has good drainage.
Plants that do well in a rock wall are varied in nature from small delicately leaved creeping plants like woolly creeping thyme thymus pseudolanuginosus or prostrate rosemary rosmarinus officinalis.
Every spring it develops masses of cheerful yellow flowers that look terrific tucked between rocks and boulders.
In warmer regions this plant can be short lived so replant every year or two.
Commonly called basket of gold perennial alyssum makes a wonderful wall or rock garden plant.
Alpine plants which often dislike wet conditions and are adapted to growing in poor soils are another option as are many wild flowers such as welsh poppy which thrive in poorer soils.
Creeping thyme is aromatic like the edible herb but it s mainly grown as a ground cover or to fill in space between stepping stones.