When to prune a lemon tree in Melbourne
The best window is late winter to early spring, roughly August to October, once the worst frosts are over and you have picked most of the fruit. Lemons flower and fruit on and off through the year, so you will always cut off a few flowers. That is fine. A light tidy-up after a heavy crop is also fine at any time of year.
Avoid hard pruning in the heat of January and February. Freshly exposed bark on a citrus can sunburn, and the tree is already under water stress.
What you need
- Sharp bypass secateurs for anything up to finger thickness
- Loppers or a small pruning saw for bigger branches
- Gloves, because most lemon varieties have thorns
- Methylated spirits or a household disinfectant to wipe blades between trees
Step by step
1. Take out the dead, damaged and diseased wood
Start with anything brown, split or covered in scale. Cut back to healthy green wood just outside a leaf or side branch.
2. Remove suckers below the graft
Most lemon trees are grafted onto a hardier rootstock. Shoots coming from below the graft union, the slight bulge near the base of the trunk, belong to the rootstock and will not give you good lemons. Cut them flush with the trunk.
3. Open up the middle
Cut out branches that cross over each other or grow back into the centre of the tree. You want light and air to reach the inside of the canopy, which helps ripening and keeps sooty mould and scale under control.
4. Shorten the long, whippy growth
Fast vertical shoots, often called water shoots, rarely fruit well. Remove them or shorten them back to an outward-facing bud.
5. Lift the skirt if needed
Branches touching the ground let ants and snails into the tree. Trim them back so the lowest foliage sits about 30 to 40cm above the soil.
How much to take off
As a rule, no more than a quarter of the canopy in one season. Citrus does not respond well to heavy cuts. If an old tree is badly overgrown, reduce it over two or three years rather than all at once.
Common mistakes
- Cutting everything back to a ball shape, which removes the fruiting wood
- Leaving stubs, which die back and invite borers and rot
- Pruning in summer heat and exposing bark to sunburn
- Feeding heavily straight after a hard prune, which pushes soft growth rather than fruit
After pruning
Water deeply, apply a citrus fertiliser in early spring and again in late summer, and mulch around the drip line, keeping the mulch a hand's width away from the trunk.
When to call an arborist
Old lemon trees that have grown taller than the roof, trees with a split trunk or heavy borer damage, or a whole row of mixed fruit trees are worth handing over. Our climbers prune fruit trees as part of regular tree pruning and trimming visits, and we can deal with neighbouring trees in the same trip.