Plant of the Month – Macaranga tanarius

Macaranga (Macaranga tanarius) also known as Bullock’s Heart because of its has large heart shaped leaves to 25cm. 

This common, very fast-growing small tree can grow to 6m and approx. 4m wide. A flush of creamish-yellow flowers from spring to summer followed by green fruit capsules with black fruit attract birds such as Silvereyes and Rosellas. Macaranga is also the host plant for the Blue Triangle Butterfly and is known to shelter Graceful Tree Frogs under the glorious leaf canopy. The local indigenous people of this area used Macaranga trunks to make fishing spears while the fibre was used for twine.

Macaranga tanarius is excellent for revegetation, screening and filling bare areas to provide cover for other plants. It prefers full or filtered sun and well-drained soil for best growth results. 

Information supplied by Coolum Native Nursery

15 Replies to “Plant of the Month – Macaranga tanarius”

    • Hi Franca,
      That’s a very good question. It is native to the area and does seem to be becoming more dominant in the past few years. This led some people to consider it to be ‘weedy’. It does tend to grow in disturbed and regrowth areas, not surprising given that it is a pioneer species. One theory is that is becoming more dominant because it likes the nutrient-rich soil created by garden run off but as far as I know that has not been scientifically verified. The prevalence of many species on the coast is changing noticeably in recent years. At this point it is difficult to know what is causing this – it may be climate and weather-related or there may be other factors at play. At this point, I would still consider Macaranga tanarius a useful native plant is it is quick growing and provides a canopy for other plants to grow.
      All the best.

      • I suggest that it is more prevalent around our urban areas as that’s where we have high disturbance. As above, it is a pioneer species and will flourish on the edges of creeks where there is disturbance (pretty much all over the sunny coast)!
        It def should be used however managed to ensure it doesn’t inhibit too much space and stop other things from poking through the canopy.

        • Sadly the three trees which I never planted grew so quickly they blocked the sun from my solar panels. Lopping them has cheared the solar panels BUT has encouraged a coppice type regrowth in my property two neighbouring properties and the Council footpath. Roundup and diesel only excites them to reproduce. Any clues on how I can kill this infestation. Thanks David

          • David,

            If you lop the Macarangas, or most trees, this cuts off the supply of a growth inhibiting hormone or auxin that keeps epicormic or growth buds dormant. Having no hormone deterrent, the buds then sprout, either from the cut trunk or as root suckers. It’s the same process when Eucalypts sprout after a fire.
            To kill the tree and prevent this regrowth we use a 50 percent strength (approx 180 mg/l) of Glyphosate and inject it into the living tree using first a 1/4 inch drill bit to drill a hole to about 20mm, making sure you are into the wood. and then a syringe (you can buy at any chemist). You can buy the full strength Glyphosate (380mg/litre) from hardware stores like Bunnings. I mix the full strength Glyphosate with water in a sealable container (an old jar with a sealable lid) I can safely carry and then fill the syringe.
            The injections are given around the base of the tree at about 80mm distance apart and into the wood of the tree. It is also important to inject under any low branches and all the root suckers that have come up.
            An alternative method is to frill the lower stem with an axe, but do not ring bark it. Then squirt the same Glyphosate concentration into the frill, which need to cut into the woody part of the stem. If the stem is too small to inject (less than about 15mm), then I have found that just cutting down to the wood at a few spots and painting on the Glyphosate works.
            This method helps transport the Glyphosate through the living tree’s vascular system to effect a kill. It usually takes about two to three weeks to get a kill, though the leaves should start to whither after a week.
            We use this method to kill several weed species here, including, Brazilian or Broad-Leaf Peppers and Camphor Laurel. For years the former, which are a real pest along our coastal areas here, were cut and poisoned but usually produced coppice or root suckers. Not any more.
            When using the Glyphosate make sure you use protective equipment, including chemical gloves and glasses.
            Hope this works for you.

  1. Hey there ?
    I have a question. We have a macaranga that has volunteered next to our dam which has many green frogs and we love butterflies ?

    Our question is, is the plant OK near a pipe running from the dam?
    If not, can we replant elsewhere?
    We’d really like to let it live.
    Thanks ?

    • Hi Louise,
      I don’t have a definite answer for you. Macarangas have a taproot as well as horizontal roots. They belong to a family Euphorbiaceae that is not generally associated with species that have invasive roots and I have not seem them listed anywhere as invasive.
      If you are concerned, you could have a go at transplanting. As a general rule, natives don’t like being moved but it’s worth a try. Or maybe another one will pop up exactly where you want it. I find that happens in my garden where I leave them if they are not going to outcompete without other natives I have growing and remove them if they are likely to overshadow.
      All the best,

  2. I call these compost trees due to the amount of leaves that drop during the normal cycle of growing.A number of years ago the council in my area decided to plant them in a library carpark and I thought you will be sorry and of course 3-5 years out they come so all those years wasted

    • Hi Philip,
      Apologies for late reply to your comment. Great name for Macanangas. I love trees that drop leaves and provide leaf mulch for surrounding plants. You’re absolutely right though. Choosing native trees, (or non-native for that matter) to use in car parks and for road landscaping requires careful consideration and a good knowledge of how plants grow, their characteristics, how long they live and how hardy they are.

  3. Are you able to advise. Noosa Council claim Macaranga trees “become unstable as they grow to a to a larger size, they often tip over and in this area they end up leaning on private fences causing damage and maintenance issues.”

    And further, “it was an unsuitable tree species issue with Macarangas”.

    The trees I am concerned about were healthy, about 10 years old and growing 1.5 m from any fence.

    Have notice that Macarangas are able to be pruned with objectionable limbs removed.

    • Hi Kevin,
      Not being an arborist, I really can’t comment on that. As Macaranagas are a pioneer species, nature probably hasn’t designed them for longevity. All trees close to properties and infrastructure do need to be checked for general health from time to time to pick up any structural weakness that may result in the shedding of limbs or destabilisation of the entire tree. If a tree is healthy, my preference would always be to trim rather than remove it whenever possible. Professional trimming generally strengthens the structure, giving a tree a good shape as well as removing height.That actually means that they are more stable and less prone to wind and storm damage.

  4. I live in adelaide wanting to know how to propagate from cuttings have not seen any seeds at all, just popped up in my garden so naturally started watering it it’s now about three metres high, want to hide six two storey units planted ten metres from our house, thank you

    • Hi Merri,
      You may just have to wait until your tree sets seed. We have always grown our macananga from seed not cuttings. The Noosa and District Landcare Nursery do the same. Unless you can get some tubestock from a native nursery down there, it might be a question of being patient.
      Kind Regards,

  5. Hi, this is a late reply, however the macarangas are seedlings are popping up everywhere in our lovely park, often under other lovely trees, along verges, on unsuspecting residents’ fence lines and gardens. I live on the Gold Coast on the Nerang river, where the council some 10 years ago planted these along the bank. Well they now seed themselves everywhere on the Gold Coast, along roadways, parks where they “push” other native plants “out”. I can’t believe such an aggressive plant was ever considered suitable. Hawaii have the right idea, and for years have classified this plant as a pest, and are seeking to irradiate and contain it. It will cost the council a lot of money to cut these down as they impact on infrastructure.

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