Pruning hydrangeas the right way
The most common reason for a hydrangea without flowers is the wrong cut. Yet the rule is simple once it is clear which group your plant belongs to: some hydrangeas set their buds the previous year, others only in spring on the fresh growth.
| Species | Flowers on | Pruning | Timing |
|---|---|---|---|
| Bigleaf hydrangea | old wood | faded flowers only | March |
| Lacecap hydrangea | old wood | faded flowers only | March |
| “Endless Summer” | old and new wood | moderate | March |
| Panicle hydrangea | new wood | hard | February–March |
| Smooth hydrangea | new wood | hard | February–March |
Group 1: bigleaf and lacecap hydrangeas
These hydrangeas already carry next summer’s flower buds at the shoot tips. Pruning in spring would remove them completely. So in March only the dried flower heads are cut back to the first strong pair of buds, plus frozen and very old shoots close to the ground.
An exception is the hydrangea “Endless Summer”: it also flowers on new wood and forgives a harder cut.
Group 2: panicle and smooth hydrangeas
These species flower on this year’s wood and tolerate hard pruning – it even encourages particularly large flowers. In late winter all of last year’s shoots are shortened to two or three pairs of buds. Weak shoots and shoots growing inwards are removed completely.
- Always cut just above a pair of buds
- Cut at a slight angle so water runs off
- Remove old, woody shoots at the base every few years
For clean cuts, sharp bypass shears are the right tool – they do not crush the shoots and the wounds heal faster.
After pruning
An organic fertiliser in April and a thick layer of bark mulch support the new growth. Anyone who wants blue flowers needs acidic soil with a pH between 4 and 5.5 – in chalky soil, blue varieties turn pink.
