Images: Tim Sandall
Ceanothus are often displayed to their best advantage when grown against a wall but plants grown this way will require pruning and training to encourage branching and flowering
Ceanothus (California lilac) are popular plants grown particularly for there bright blue flowers although other flower colours are available. There are both evergreen and deciduous species and cultivars. Most are hardy in the UK but need shelter, especially in frost pockets or exposed gardens. Ceanothus thrive best in a free-draining light soil in full sun.
Many evergreen Ceanothus such as C. ‘Autumnal Blue’ or C. arboreus ‘Trewithen Blue’ have spreading habits, which benefit from some sturdy support and are shown to their best advantage when trained against a wall. If this type of Ceanothus is not trained the plant often grows away from the wall and becomes unruly or even unsightly (left).
Wall training a Ceanothus
When planting try to avoid putting the root system closer than 45cm (18in) to the base of the wall in order to avoid the dry rain shadow. Remove any canes or ties from the plant. Tie the plant to its new support starting with the main stems, then well-placed laterals (left).
Remove, or shorten to one to two buds, stems growing directly outwards, those growing inwards towards the wall and any stems that cannot be tied in (right).
Pinch out the tips of young, forward-growing shoots to encourage sideways branching. Shorten the longest laterals by a few buds particularly where there is space. This will stimulate branching and balanced cover.
In the following years tie in new growth where possible. In spring remove older wood that has become unproductive to make way for younger, stronger growth. Shorten weak growths to stimulate stronger branches. Prune flowered shoots as appropriate, and prune out congested growth to lrt in light and air.
Check ties and reposition or replace as necessary.
Sarah Durrant