Eucalyptus punctata (Grey Gum) Growing Guide

What is Eucalyptus punctata?

Also called grey gum, Eucalyptus punctata is one of Australia’s most iconic trees. Its lance-shaped leaves have a willowy flow that dapples natural light across gardens and parks in spectacular style. But it doesn’t stop there, this wonderful tree, which grows to around 30m tall if left to maturity, can be treated equally well as a coppiced hedge and has a multitude of structural and medicinal uses.

For me though, the best, and only use, for this wonderful specimen tree is as an ornamental fully-grown tree in a space that’s large enough to accommodate its full form.

Flowers and seeds form in groups of seven, with white myrtle-like flowers appearing from December through to March, followed by distinctive cup-shaped seed pods.

The leaves are useful for identification purposes, partly because of their curved lanceolate form, but also because they are so regularly frequented by koalas, who seem to prefer grey gum above all else.

What is Grey Gum’s Natural Habitat?

Eucalyptus punctata is endemic to Eastern Australia, with a preference for coastal areas, ranging from Nowra in New South Wales to Gympie in Queensland.

In nature, it thrives on very poor, free-draining soils, ranging from sand to shale, but it can cope with loam and reasonably rich garden soil too provided it isn’t waterlogged while young.

As a general overview, Eucalyptus punctata is a subtropical, coastal tree, but its range does extend beyond that, and it will grow in a variety of other conditions.

Common Uses for Eucalyptus punctata

There are medicinal, structural and horticultural uses for Eucalyptus punctata, but its most beneficial purpose is to serve as a wildlife-friendly tree. This offers an essential food source for koalas, who will choose its leaves over other Eucalyptus, and a nesting habitat and food source for the grey-headed flying fox, which eats the flowers as a nutrient source, but also as a nectar-rich energy boost.

Several native birds benefit from the sap, bark, foliage and flowers of grey gum too, including the noisy firebird, red wattlebird and both yellow-tufted honeyeaters and brown-headed honeyeaters, which feed on the gum that seeps from the stems.

As a firewood, it burns fast but hot, making it a useful fire starter, but also a potential fire risk. The timber is incredibly strong and has traditional and modern uses in landscape works, including fences and joinery, but also as a subtly grained finishing timber. 

Edible Uses & Identifying Eucalyptus punctata

Eucalyptus punctata leaves, essential oil, and bark are toxic, but in low quantities, the leaves can be brewed into a herbal tea. The only safe part of the tree for human consumption is the manna that exudes from the stems, which can be harvested as a wet gum, or once dried as a sugar substitute. 

To identify grey gum, begin with the bark. It will be peeling with grades of grey bark in different layers. The upper branches should be grey, with similarly coloured shoots.

Young leaves are wider, but with a slight curve to their pointed tip, while mature leaves are distinctly lance-shaped, with a clear curve. Flowers and seed pods form in groups of seven.

How to Grow Eucalyptus punctata

This Eucalyptus species is most at home in poor sandy soils in warm coastal areas, where there is some fluctuation between seasons. However, like most eucalyptus trees, it will grow in a wide variety of conditions and be very hardy once established.

In the following guide, we’ll look at everything from creating the right soil conditions to pest control, as well as a detailed guide on propagating your own grey gum trees at home.

There are some notes worth remembering as you go through, particularly around propagation and pest control, where some traditional pest control methods could have potentially deadly effects on beneficial and essential native wildlife.

Ideal Conditions for Growing Eucalyptus punctata

Let’s start by looking at positions and conditions. Eucalyptus punctata will grow best in its native setting but can be grown anywhere in Australia. However, as with all Eucalyptus, there are some common-sense restrictions on how and where to do this, as they can outcompete, cross-pollinate and spread, competing with other native species in their own native range. 

While there are no particular concerns around E. punctata, be mindful of what classes as native and where across our diverse and precious country.

Soil & Drainage

Poor soil doesn’t mean bad soil, but nutrients are not high on the priority list of Eucalyptus punctata. It will spread its shallow roots far and wide to find what it needs, so treating young trees harshly will usually help them establish faster.

If you have heavy clay, loamy soil, or rich, well-mulched garden conditions, add plenty of grit and sand to the soil before planting. As saplings or young trees, Eucalyptus punctata need to be encouraged to grow outwards, so the only preparation required is to dig a wide hole and restrict nutrients in the immediate area.

Note: In practice, Eucalyptus punctata can usually be planted anywhere with no preparation, but do avoid heavy soils and very nutrient-rich conditions with high moisture retention as it will put young trees at risk.

Light & Temperature

Eucalyptus punctata likes full sun but will compete for it. That means you can plant them anywhere in dappled light, part shade, or full sun and they will grow. Just avoid very shady spots, as they can struggle to establish without an obvious route to the light.

This species is hardy down to -10°C and very drought tolerant, so there are no particular considerations when planting these native trees in any part of Australia. If there is a shock frost that is expected to last beyond two or three days, cover saplings with fleece.

Shelter

As a tree that grows in mostly coastal areas, Eucalyptus punctata is remarkably resilient to wind, saline, salty, air and anything else the weather can throw at it. It is regularly stripped bare by koalas and will recover in astoundingly quick time.

So don’t be shy about where you plant it, and don’t worry too much about protecting young trees.

Planting Eucalyptus punctata

As mentioned above, planting this species is all about encouraging it to grow away from the planting hole. So dig a hole that is at least twice the width of the root ball, if not three times wider. 

Make the appropriate adjustments to the soil (sand or grit if it is heavy or moisture-locking), and then plant it. That’s it. Then heel it in well, and provide a standard tree take for the first couple of years to prevent rocking while the roots anchor the tree in. 

The idea is to encourage lateral root growth, as these trees have shallow, spreading roots that feed from a wide area, rather than seeking deep water.

How to Propagate Eucalyptus punctata

Propagating Eucalyptus punctata is easiest from seed, but the most reliable method is grafting. Cuttings are possible but unreliable, but there are some growers who had success by propagating cuttings from young trees when the new growth is most susceptible to change.

Propagating Grey Gum from Seeds

Eucalyptus punctata seeds are plentiful. If you have access to a tree with fresh seeds, they are always more reliable than packaged seeds, and neither should need chilling before planting.

Simply sprinkle the seeds onto a well-drained compost mix (we use a mix of about 75% coco coir, and 25% perlite (perlite rather than vermiculite, as it retains its structure and drainage properties for far longer). 

The earlier you can harvest the seeds and start this process the better, as they will germinate outdoors in full sun, so long as the compost is kept slightly moist until they germinate.

Once germinated, allow them to grow to about 10cm tall in the tray before pricking out into individual pots. After that, move them only when the roots have filled the pots, as eucalyptus trees don’t like root disturbance.

Eucalyptus punctata Propagation from Cuttings

Most Eucalyptus species will not root from cuttings, but we went against the received wisdom and managed to root several cuttings last year, with about a 10% success rate.

Rooting hormone gel is essential for this, and the cuttings should be dipped in gel and planted within minutes of being cut from the tree. Eucalyptus stems dry out quickly, so time is of the essence.

Cuttings should include budding leaves, and no flowers or developing seeds. Take cuttings that are about 15cm long, cutting just below a node. 

Immediately dip the cut end into rooting hormone, and then place it into a pot filled with a fine-grade coir compost and perlite. Keep the soil moist, but don’t overwater, and store them somewhere bright but away from direct light, at temperatures of roughly 15-21°C.

Rooting takes a few weeks, so be patient. Check the roots when new growth appears.

Note: The most reliable cuttings can be taken from the side shoots of young trees when they are around twelve months old. Always cut to a node for better rooting potential.

Propagating from Grafted Cuttings

If cuttings don’t work, you could try grafting. If you’ve not tried grafting before, there are easier trees to graft, like apples, cherries and figs for example, but the basic technique is the same.

You can graft onto a living rootstock, without harming that tree, but will get better results from direct grafting, meaning that you use the rootstock of a 12 to 24-month-old tree, remove its top growth, and attach a fresh cutting into a groove in the lower tree. 

This can be attached with tape, tight twine, or wax, and new growth usually appears within weeks. The main benefit of this is that the rootstock is already growing, and able to process nutrients for a more mature tree. 

Growth rates are improved, and the disease resistance of young eucalyptus trees from grafts is much greater than from cuttings of seeds of the same age.

Caring for Eucalyptus punctata

Depending on how you choose to grow your Eucalyptus punctata, or grey gum, the way you care for it will change. Up to this point, our advice has been on how to establish and propagate, but here, you’ll need to decide on whether you want to grow these trees to maturity or coppice them into a shorter hedge.

Personally, I would suggest using other Eucalyptus for this purpose, simply because coppicing grey gum completely wastes its potential bark colouring and patination, and the foliage will never reach the same curling glory of its mature potential.

But, in smaller gardens, coppicing is a great way to fit a wider variety of species in, and birds will still benefit from the foliage.

Coppicing Eucalyptus punctata

If you are unfamiliar with coppicing, it just means cutting back hard, to encourage fresh new growth. It’s a technique used for millennia across the world for growing firewood and kindling, craft materials for weaving and rope making. 

In modern horticulture, it is mainly used to celebrate the stem colour of certain species, which have richer stem colourings on young growth, and to grow informal hedges and boundary planting.

There are two ways to coppice Eucalyptus punctata. First is hard coppicing, by pruning young trees into multi-stemmed trees at the time of planting, and then cutting right back to that point every year. By summer, you’ll have full new growth, and by winter it can be in flower again.

The second is to cut back half of each plant each year. So there is always structure. Alternate the side of the plant that gets pruned for constant evergreen foliage, paired with rotating fresh growth.

Common Grey Gum Pests and Diseases

There are no common, widespread pests or diseases that specifically target Eucalyptus punctata. It can suffer from root rot due to poor drainage and crown rot when coppiced, and like most Eucalyptus, it is moderately susceptible to canker and common fungal infections of the leaf, such as verticillium or fusarium.

Most problems are the result of pest damage, which will usually be spread by psyllids or leaf-boring insects, including gall wasps, which lay eggs inside the leaves of eucalyptus plants.

However, because these trees are such an important food source for native wildlife, including birds, flying foxes and koalas, they should never be treated with any form of pesticide, whether it is organic or chemical.

Pests on young trees can be managed easily with manual removal. This includes removing leaves with galls, or that show evidence of pest damage. On mature grey gum, pests should be tolerated and will cause very little harm to the plant in the long term.

Eucalyptus punctata Frequently Asked Questions

What is grey gum timber most commonly used for?

Grey gum, or Eucalyptus punctata, is most commonly used for structural timber, rather than delicate joinery. It is often used for railway sleepers and retaining beams, as well as floorboards and butcher's block countertops.

Is grey gum the same as grey box?

Grey gum and grey box are different plants. Grey gum refers to Eucalyptus punctata, the grey-barked, flaking trees most commonly associated with koalas and flying foxes. Grey box refers to Eucalyptus moluccana.

Are Eucalyptus punctata roots invasive?

Eucalyptus punctata roots are not especially invasive, but they are wide-spreading, and search stubbornly for water. They should not be planted within 30m of a house, but won’t typically lift paving or other hard standing.

Is Eucalyptus punctata an invasive species?

Eucalyptus punctata is not an invasive species, but it is only endemic to eastern Australia and may have some impacts on other native species when planted outside of its natural range. It is not specifically noted as a tree of concern.

Is Eucalyptus punctata hardy?

Eucalyptus punctata is hardy down to -10°C, and very drought tolerant. It should be suitable for planting in most Australian climates without protection.

Is Eucalyptus punctata hard to grow?

Eucalyptus punctata is not hard to grow. It grows well in most conditions, and mature trees are very resilient. If you have space in your garden, they make exceptionally lovely ornamental trees if left to their full size.

Is Eucalyptus punctata toxic to pets?

Eucalyptus punctata is toxic to most household pets, including dogs, cats and rabbits. The wildlife that feeds on it, and all other species of Eucalyptus is specifically adapted to cope with the toxic effects of the foliage. Do not allow your pets to consume any part of the plant.

How long do Eucalyptus punctata live for?

Eucalyptus punctata is a long-lived tree, with many wild trees at least 400 years old. Some Eucalyptus trees are known to be several thousand years old, so any you choose to plant is a massive investment in the future.

Can you eat Eucalyptus punctata leaves?

There are some reports of tea being made from dried Eucalyptus punctata leaves, but they are not specifically recorded as safe to consume. Most eucalypts are toxic in all parts other than nectar and manna, but in very low quantities tea made from the leaves is safe.

When can you harvest Eucalyptus punctata seeds?

The best time to harvest Eucalyptus punctata seeds is between April and June, after flowering, and before the weather is too humid. This should give the trees enough time after flowering to produce dried seed pods, ready to sow.