Pruning perennial delphinium
Advice for October in the Netherlands
Perennial delphinium can have its spent spikes removed after the first flowering for possible repeat bloom. In spring, clear only dead remains and protect young shoots. The months are a guide for gardens in the Netherlands and Belgium; growth stage and weather take priority.
Perennial delphinium — October
Check this first
Keep green leaves and developing flower stems intact. Leaves that die completely after the first frost can be cleared then or during the spring tidy.
Pay attention to this
- Wear gloves; delphinium is harmful if swallowed and can irritate skin.
- Check young basal shoots for slug damage before assuming the clump is dead.
- Retain support for tall stems still flowering while removing spent stems.
Frequently asked questions
- Can I pinch out the top before flowering?
- Not if you want to retain the normal tall spikes. The summer cut described here comes only after flowering.
- Must I leave only five shoots?
- No. Thinning for exceptionally large spikes is a specialist option for strong mature clumps, not a compulsory maintenance step.
- Does this cover annual larkspur?
- No. This covers perennial delphiniums in the Elatum Group; annual plants have a different life cycle.