Pōhutukawa Pruning and Care: Roots, Leaf Drop, Rātā and Myrtle Rust

A big pōhutukawa can live beside a house for generations if it is pruned lightly, at the right time of year, and its roots are mostly left alone. This guide covers when to prune, how much to take, what the roots and flower drop really do, how to tell pōhutukawa from rātā, and what to do if you spot myrtle rust. Small jobs you can plan yourself; the bigger cuts are work for tree pruning specialists. If you aren’t sure you’re allowed to touch the tree at all, start with our guide to pōhutukawa rules and consent.

When is the best time to prune a pōhutukawa?

Autumn to early winter. Auckland Council asks people to limit pruning of myrtle-family trees, pōhutukawa included, to that window, because cutting triggers soft new growth and myrtle rust attacks soft growth, most aggressively in the warmer months. Pruning then also keeps clear of the spring growth flush and the summer flowering. Outside that window, cut only for safety: a cracked limb or a branch grinding on the roof can’t wait.

Whenever you prune a pōhutukawa, the council’s hygiene advice applies: clean saws and loppers with methylated spirits or a 5–10% bleach solution after the job, and don’t cart the prunings off to another property if anything on the tree looks like rust. Ask any contractor to do the same between sites.

How much can you cut off a pōhutukawa?

Less than most people expect. Pōhutukawa take selective cuts well: thinning the canopy, lifting the lowest limbs, or shortening a branch back to a healthy side branch to clear a roofline. They take heavy cuts badly. Topping, or a big reduction into old wood, produces a thicket of weak regrowth, leaves large wounds that decay, and spoils the tree’s broad, spreading form for good. Take a little each year, not a lot at once.

The regrowth is the real trap. After a hard cut, a pōhutukawa throws dense clusters of epicormic shoots from buds under the bark around each wound. They grow fast, but they are anchored only in the outer wood, so they break out easily in wind and need thinning for years afterwards. A sensible ceiling, even on an unprotected tree, is the one Auckland’s plan sets for scheduled trees: small cuts, and no more than about a tenth of the foliage in a year.

What branches should you cut?

• Dead, dying and broken branches, at any time of year.
• Branches that cross and rub, wearing bark off each other.
• Low limbs over paths, the driveway or the lawn, lifted to a set clearance.
• Branches resting on the roof, gutters or walls, cut back to a side branch well clear of the house.
• Crowded water shoots left by earlier hard pruning, thinned to a few well-spaced ones.

Common pōhutukawa pruning mistakes

• Topping the tree, or cutting main limbs back to stubs.
• Cutting in the wrong place: hard against the trunk, or so far out that a dead stub is left behind.
• Tearing bark by dropping a heavy limb in one cut instead of taking the weight off first.
• Taking too much at once, which leaves the tree short of leaf.
• Pruning in spring or summer, when new growth is most exposed to myrtle rust.
• Not checking protection before cutting a big coastal tree.

Do you need consent to prune a pōhutukawa?

Usually not. You may need it if the tree is a scheduled notable tree (light trimming within strict limits is still allowed), is over 3 m tall and within 20 m of the high-water mark, stands within 10 m of an urban stream, or sits inside a Significant Ecological Area. The rules and consent guide linked above sets out each limit and how to check your address. Read it before booking anything bigger than a tidy-up.

Are pōhutukawa roots invasive?

Not in the way people fear. Pōhutukawa roots spread wide and stay shallow rather than driving deep, and they follow moisture. That makes them good at lifting paths, patios, low walls and driveways, and poor at harming sound modern foundations. They get into drains only where a pipe is already cracked or a joint has failed. Most root problems can be fixed at the surface, without taking the tree out.

Two cautions. Cutting roots inside the protected root zone of a notable tree is a consent matter, and on any pōhutukawa the big structural roots near the trunk should be left alone. And the roots suffer from compaction: the Department of Conservation lists parking cars on the roots among the ways people damage these trees, so keep vehicles, spoil heaps and new paving off the root area where you can. Our guide to tree roots, drains and foundations covers the general picture for all species.

Do pōhutukawa have aerial roots?

Yes. The fibrous roots hanging from the trunk and branches, sometimes in thick curtains, are normal for the species and not a sign that anything is wrong. The NZ Plant Conservation Network’s description of mature trees mentions branches carrying “brooms” of them. Leave them be, and trim only the ones that hang into a gutter, a doorway or a path.

Leaf, flower and stamen drop: gutters and drains

Pōhutukawa shed leaves all year and drop a heavy fall of spent red stamens after flowering around Christmas. On a roof, that means blocked gutters and downpipes every summer. The fixes are routine: gutter guards, a clean once flowering has finished, and lifting or thinning the branches directly over the roof so less lands there. None of it requires losing the tree.

Shedding is also not a ground council accepts for removing a protected tree, so plan to manage it. If the tree is a neighbour’s and its flowers keep filling your gutters, talk first. As a last resort, the Property Law Act lets a court order a tree trimmed where fallen leaves or flowers unduly obstruct a gutter or drain; our guide to a neighbour’s overhanging tree explains how that works.

Can you grow pōhutukawa as a hedge?

Yes, if it is planted and clipped as a hedge from the start. Pōhutukawa is a coastal tree, so it suits shelter hedges on exposed seaside sections. Clip lightly and often, in the same autumn-to-early-winter window as any myrtle, and clean your tools afterwards. What doesn’t work is turning a mature tree into a hedge: the hard cuts that would take are exactly what this species handles worst.

A pōhutukawa hedge is still a row of native trees as far as the coastal rules are concerned, so a waterfront hedge that has grown past 3 m can need consent to cut back hard. For regular clipping of a hedge that is already established, see hedge trimming.

Is pōhutukawa good firewood?

It is a dense native hardwood, generally regarded as burning hot once it has been split and well seasoned. The more important question is where the wood came from. Only burn pōhutukawa from a tree that was lawfully removed, or a branch that came down on your own property. Never cut live wood from a reserve, beach or roadside tree, even one that looks overgrown.

The Department of Conservation names people taking branches for firewood, and lighting fires under the trees, among the threats to pōhutukawa. If you have wood from a lawful removal, stack it under cover with air around it and let it dry thoroughly before burning it.

Rātā vs pōhutukawa: how to tell them apart

Turn a leaf over. A mainland pōhutukawa leaf is thickly coated underneath in fine white hairs, and that is the Department of Conservation’s quick way to tell it from rātā. Both belong to Metrosideros, part of the myrtle family (Myrtaceae), and both flower red around early summer. Where their ranges overlap in the upper North Island, pōhutukawa and northern rātā hybridise, so some trees sit in between.

Based on the Department of Conservation’s pōhutukawa and rātā pages and the NZ Plant Conservation Network’s species descriptions.

What are the two types of pōhutukawa?

The Department of Conservation counts two: mainland pōhutukawa (Metrosideros excelsa), the tree on Auckland’s coast, and Kermadec pōhutukawa (M. kermadecensis), native to Raoul Island in the Kermadecs. According to the NZ Plant Conservation Network, the Kermadec species has smaller, rounder leaves, a more upright and shrubby habit on the mainland, and a habit of flowering on and off through the year.

What myrtle rust looks like on pōhutukawa, and who to tell

Myrtle rust is a fungal disease of the myrtle family, caused by Austropuccinia psidii. It was first found on mainland New Zealand in May 2017, and in April 2018 MPI moved to long-term management because containment had proved impossible. On pōhutukawa, look on soft new leaves and shoots for bright yellow, powdery spots. If you see them, don’t touch, cut or move anything. Photograph it and report it.

• Report it through the iNaturalist app or to Auckland Council’s biosecurity team at biosecurity@aklc.govt.nz. MPI’s exotic pest and disease hotline, 0800 80 99 66, also takes reports.
• Don’t move it. The spores spread on contact and in the wind, so leave suspect plants, prunings and green waste where they are.
• Don’t try to treat or cut it out yourself. Auckland Council’s page on protecting plants from myrtle rust points to the official guidance on handling infected plants.
• Clean up after any myrtle work with methylated spirits or 5–10% bleach, and wash work clothes in hot water.

Rātā, mānuka, kānuka, feijoa and lilly pilly are all hosts too, and ramarama and rōhutu are especially at risk, so a report from your garden helps track the disease across the whole family.

Why is my pōhutukawa dying back?

In a garden, the usual causes are possums browsing the foliage, root damage from new paving, trenching or parked cars, dry spells on thin soils, heavy pruning, and myrtle rust on new growth. The Department of Conservation notes that intensive possum browsing can kill a mature tree in about three years. Chewed shoots and thin crowns point to possums; dieback after building work points to the roots. If the dieback is spreading, large limbs are dying, or there is decay or fungus at the base, get an arborist to look at it, and check the signs a tree is dangerous in the meantime.

If your pōhutukawa needs more than a tidy-up, book a pruning quote. We will tell you which cuts the tree actually needs, and whether any of them need consent first.

General information about caring for pōhutukawa, not advice about your specific tree. Confirm protection with Auckland Council before any significant work. See our disclaimer.

Frequently asked questions