Short answer
Fix a string line between two canes at the height you want, cut the top level with it, then work down the sides with a slight taper. Check by standing back from several angles.
Method 1: string line (most hedges)
- Push a cane into the ground at each end of the hedge.
- Tie a string tight between them at the height of the finished hedge. Add intermediate canes on long runs.
- Cut the top just below the line, keeping the blade flat.
- Move the string down the side for vertical edges if needed.
Method 2: template for formal shapes
For shaped or curved tops, make a simple wooden template and hold it against the hedge as a guide. This is useful on box and yew.
Method 3: spirit level
For a level top on a sloping garden, use a long straight board and a spirit level to set the height at intervals.
Cutting technique
- Use long, smooth sweeps.
- Keep the blade angle consistent.
- Overlap each pass slightly.
- Work towards you for the final trim of the top so you can see the line.
Common mistakes
- Cutting without a guide.
- Over-reaching, which tilts the blade.
- Using blunt blades that snag.
- Cutting a flat top wider than the base.