Foam of May (Spiraea × arguta): when and how to prune

Foam of May (Spiraea × arguta): when to prune it?

JFMAMJJASOND

Straight after flowering, at the end of May. It flowers on the previous year’s wood.

What else to prune in those months? May

Foam of May (Spiraea × arguta): how to prune it?

1. Cut flowered stems back to a strong, young side shoot lower down.
2. Every year, remove a quarter to a third of the oldest stems right at the base.
3. Keep the long young shoots: they will flower next spring.
4. An old, neglected shrub can be cut back to 20–30 cm straight after flowering; it will flower less the following year.

How much to cut, and how often?

• One pruning period a year: May.
• Prune in moderation: never remove more than about a third of the shrub at once.

What does it mean for wildlife?

• Pruning in May can fall in the nesting season (15 March–15 August). Check carefully for nesting birds first: disturbing an active nest is against the law.
• Foam of May (Spiraea × arguta) flowers in April–May, 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.
• Prunings can go on a dead hedge or brash pile in a corner of the garden: shelter for hedgehogs, wrens and insects.

Common mistakes

• Clipping without first checking for nesting birds.
• Leaving a stub or sawing flush with the trunk: cut just outside the branch collar.

Nearby: related pruning guides

• Spiraea
• Japanese spiraea
• Spiraea (Spiraea × cinerea)
• Thunberg spiraea (Spiraea thunbergii)
• Birchleaf spiraea (Spiraea betulifolia)
• Bridal wreath (Spiraea × vanhouttei)

Plant profile: Foam of May (Spiraea × arguta) · Pruning calendar and basic rules