UK pruning guide · RHS timing
When to prune citronella grass in the UK
Why the timing differs here
British pruning timing is set by the last frost rather than the calendar. The RHS advises against winter pruning for most plants because it pushes out soft growth that a late frost then kills — and UK last frosts run from March in the south-west to mid-May in the north.
How to prune citronella grass
Use shears or a sharp knife to cut the entire clump back to 4–6 inches above the ground. Remove dead outer leaves by pulling or cutting them away at the base throughout the growing season.
Citronella grass benefits from annual cutting back to rejuvenate growth and remove dead material. Cut the clump down to 4–6 inches in late winter or early spring before new shoots emerge. During the season, remove any brown or dead outer blades to keep the clump tidy. Divide congested clumps every 2–3 years.
More citronella grass care for British gardens
Care at a glance
Pruning citronella grass in the UK — FAQ
When should I prune citronella grass in the UK?
Prune citronella grass in spring, once growth resumes. British pruning timing is set by the last frost rather than the calendar. The RHS advises against winter pruning for most plants because it pushes out soft growth that a late frost then kills — and UK last frosts run from March in the south-west to mid-May in the north.
Is it illegal to prune citronella grass in spring or summer in the UK?
There is no nesting-bird restriction that realistically applies to citronella grass, since birds do not nest in it. The Wildlife and Countryside Act 1981 still protects any active nest you do find anywhere in the garden — the rule is about the nest, not the plant.
How do you prune citronella grass?
Use shears or a sharp knife to cut the entire clump back to 4–6 inches above the ground. Remove dead outer leaves by pulling or cutting them away at the base throughout the growing season.
How often does citronella grass need pruning in a British garden?
Annually (hard cutback); tidy dead blades as needed during the season. Citronella grass benefits from annual cutting back to rejuvenate growth and remove dead material. Cut the clump down to 4–6 inches in late winter or early spring before new shoots emerge. During the season, remove any brown or dead outer blades to keep the clump tidy. Divide congested clumps every 2–3 years.
Why is UK pruning timing different from American advice?
Most pruning guides online are written for US conditions and anchored to USDA zones. Britain's maritime climate gives milder winters but later, less predictable last frosts — from March in the south-west to mid-May in the north — so the RHS advises against winter pruning for most plants: it pushes out soft growth that a late frost then kills. Britain also has the nesting-bird law, which has no US equivalent.