Key takeaways
- Most evergreen hedges do best with a trim in late spring and again in late summer or autumn.
- Fast growers and formal shapes may need a third trim during the year.
- Avoid trimming in hot, dry spells or long stretches of wet, humid weather.
The best times to trim
Most hedges in Auckland are evergreen, and they generally do best with two main trims a year:
- Late spring, once the first flush of new growth has firmed up. This sets the shape for summer.
- Late summer to autumn, to tidy up summer growth before things slow down for winter.
A light tidy in winter is fine for evergreen hedges if they start to look shaggy. Box hedges usually need two or three light trims through the growing season. Deciduous hedges, which lose their leaves in winter, are trimmed just after each burst of growth, usually in mid spring and late summer.
How often should you trim?
Two trims a year suits most hedges. Fast growing hedges and formal shapes, like low box borders or square-cut privacy hedges, often need a third trim to stay crisp. Regular light trims keep a hedge denser than one big cut back.
Weather to avoid
Hot, dry days can scorch fresh cuts and the inner leaves a trim exposes. Long spells of wet, humid weather slow healing and can encourage fungal problems. A mild, overcast day is ideal.
Getting the shape right
Trim so the hedge is slightly wider at the bottom than the top. This lets light reach the lower leaves, so the base stays full instead of going bare. A string line pulled tight between two stakes helps you keep the top level.
Bringing back an overgrown hedge
If a hedge has got away on you, it's usually best to reduce it in stages over a season or two rather than all at once. Many conifers don't grow back from bare brown wood, so cutting them back too hard can leave permanent gaps. If you're not sure how your hedge will cope, send me a photo and I'll let you know.
Staying safe
- Set ladders on firm, level ground and don't overreach.
- Keep both hands on the trimmer and wear eye and ear protection.
- Check for power cables, fences and anything hidden in the hedge before you start.
Tall or long hedges are where most DIY trims go wrong. That's a good time to get me in to do it.