Photo: Barnes, Dr. Thomas G., Public domain · source
Pruning guide · Perennial
Cardinal flower: when and how to prune
Lobelia cardinalis
Cardinal flower is best pruned in August and October.
| Pruning months | August and October |
|---|---|
| Flowering | July–September |
| Good for bees, butterflies and birds | Yes, for bees |
| Native to Belgium | No, planted |
| Poisonous to people and pets | Yes, take care with children and pets |
Cardinal flower: when to prune it?
It is hardly pruned. In August, cut back spent spikes, and in October, after flowering, cut the stems down to just above the leaf rosettes.
Cardinal flower: how to prune it?
- In August, cut spent spikes back to just above a side shoot for more flowers.
- In October, cut the stems back to just above the rosettes at the base.
- Do not damage the rosettes: the plant grows again from them next year.
- Then cover the rosettes loosely with leaves.
How much to cut, and how often?
- There are 2 pruning periods a year: August and October. You don’t have to prune in every one.
What does it mean for wildlife?
- Cardinal flower flowers in July–September, when it attracts bees.
- If pruning falls during flowering, wait until it is over or leave part of the plant to flower, so bees and butterflies still benefit.
Caution: Wear gloves and wash your hands afterwards: the plant is poisonous.
Nearby: related pruning guides
Plant profile: Cardinal flower · Pruning calendar and basic rules
This guide is compiled from the Bladwijzer plant profile and pruning calendar.