Delonix regia

Family:     Fabaceae   Origin: Poincianas are native to Madagascar

The common name Poinciana comes from the tree originally being placed in the genus of the same name. It has also been called flamboyant and, along with many other trees, flame tree.

It has become naturalised in many countries into which it has been introduced, especially in Asian countries near the equator: in China, for example. For this reason it should be treated with some caution by responsible gardeners in Brisbane.


Growth form

Royal Poinciana, in good climates, grows up to 9 to 12 metres high. They have a wide umbrella canopy that usually grows wider than the tree is tall. This has made poinciana useful in hot climates as a shade tree because of its height and thick, wide canopy of leaves. Poincianas have a tendency to develop dead wood that attracts borers when pruned internodally: call us if you need a Brisbane arborist to prune dead wood from your poinciana.


The poinciana has a relatively smooth trunk of a light brown color. It can start branching too low to the ground for people to walk under it, so should be pruned while still juvenile to eliminate low scaffold branches.


For several weeks in spring and summer Poinciana is covered with exuberant clusters of flame-red flowers, 10 to 12 cm across. Even up close the individual flowers are striking. They have four fan-shaped scarlet or orange-red petals about 7.5 cm long, and one upright slightly larger petal–the standard–which is marked with yellow and white.

The flowering ability of a tree is determined by age, genetics and environment. Poincianas shouldn’t be expected to bloom until reaching at least six years of age, sometimes older. If they have been grown from a parent or parents with good flowering genes they should flower prolifically with, ironically, either good nutrition or under stress.

Poinciana flower
Close up of a poinciana flower


The poinciana’s compound leaves are striking. They are lacy and fernlike, bipinnate, and 30.5 to 50.8 cm long with 20 to 40 pairs of primary leaflets, each divided into a number of pairs of secondary leaflets.
poinciana foliage


Being in the Fabaceae family, Poincianas are legumes so their fruit really is a bean. Their seeds start out green and soft, but become brown and woody as they age. They look like flat pods up to 60cm long and 5cm wide).



Poinciana are commonly propagated by soaking the seeds for up to 24 hours in water before planting them in warm, moist soil. Instead of soaking, the seeds can also be nicked open allowing water to get inside the pods, and then planted immediately.

An alternative method is to take a branch and cut it into 30 centimeter long sections, and then plant those in soil. Rooting hormone (auxin) will aid the cutting to take hold.


The Poinciana requires a tropical or near-tropical climate and full sunlight, but can tolerate drought and salty conditions. Poinciana prefers an open, free-draining sandy or loamy soil enriched with organic matter. The tree does not like heavy or clay soils and flowers more profusely when kept slightly dry. It is also tolerant of somewhat acidic and alkaline soils.

Phosphatic fertilizer can aid in flowering and can be applied at the start of Spring. Juveniles can also be fertilized in Summer and Autumn with a 15:5:15 or similiar fertilizer. Growing Poincianas is an exercise in balance. We also apply organic fertilizer subterraneously when pruning poincianas to aid their recovery.

Poincianas grow relatively fast, around 1.5 metres a year.



Poncianas are susceptible to borers that usually attack Australian natives. They should be examined externally for tell-tale borer holes. Peel aside a little bark from any damaged wood and look for pin-holes.

Borers can be killed mechanically by poking wire down the hole if caught early. Usually, it’s better to have us treat the tree by injecting an insecticide which is absorbed by the tree and kills the borers as they eat the wood.

If in doubt, have us examine the tree as we can use instruments to check for internal borer activity. If left untreated, Poincianas may collapse due to damage to the heartwood and the resulting rot.
poinciana borer close-up

Brown Root Rot

Poincianas can also be attacked by the same Fusariam fungus that causes brown root rot, killing many jacarandas in Brisbane’s parks a few years ago. The Brisbane City Council has established a management plan using a Trichoderma species of fungi, though it is still in a trial phase. The DPI are extending the trial to other regions and will publish results in 2016. Officially, removal of affected trees on private property is currently recommended.

Poincianas should not have mulch with pieces of wood greater than 25mm length applied to the soil within its canopy as this can aid in transmission of the Fusarium fungus.

Further reading and sources

Schwarze, Francis WMR, et al. “Evaluation of an antagonistic Trichoderma strain for reducing the rate of wood decomposition by the white rot fungus Phellinus noxius.” Biological Control 61.2 (2012): 160-168.

David’s field notes

Perhaps the biggest issue I see from day to day with Poincianas is poor pruning technique. Poinciana branches that have been cut out from the trunk will do one of two things. Firstly, they can simply die, becoming dead wood that later falls from the tree. Until they fall they expose the tree to the entry of bacteria, fungi, insect and borer attack.

Secondly, and even more commonly, watersprouts will grow from the cut branch. Poincianas have strong epicormic growth; that is, they have dormant buds along the branches. As a result new, spindly branches grow much faster than the section that was removed so the property owner has to have the tree pruned regularly. This is another example of it being more economical to have something done right, the first time.

Further, poor pruning practices destroys the structural integrity of the tree as solid watersprouts are prone to snapping. I recommend only having Poincianas pruned by an arborist.

162 thoughts on “Poinciana”

  1. We have a beautiful poinciana tree we planted 20years ago! We live in the Lockyer valley. Our tree has developed borers in some branches and branches have died. My husband cuts them off when this happens. I am concerned that the tree has developed a fairly large hole in one of the 3 trunks. We have never had anyone to look at the tree. Can you advise me please?

  2. Hi David,

    I bought a Delonix Regia 1000L from QLD and had it trucked to Sydney, Lower North Shore. It has lost all its leaves and it looks bare we are about to get in planted in a couple of weeks but shore if the tree will make it. The stems are still browny green though. I always water it and I have fertilised it too. What are you thoughts?


    1. I grow several poincianas in Sydney and have seen them flower in Liverpool and various suburbs. Just be patient, it will grow fine once it has settled in. It won’t resprout leaves till mid-October.

  3. Hello,

    I am looking for some advice in regards to our very large Poinciana tree in our back yard. As the tree has a very large and often very thick canopy it is difficult to grow anything directly under it (including grass). We recently decided to create a very large raised garden bed around it (13m x 8m). We raised the soil in some parts by 10cm and others 20cm, then added 5cm of wood chip. We kept the soil and mulch back from the main exposed roots at the base of the tree, but of course some raised roots further out have been covered. The soil we used was turf underlay on top of the original hard clay soil. Will this amount of soil cause problems for the tree or will the roots further out from the tree find there way up out of the clay soil to the softer top layer? We are in the Mullumbimby area which is probably a bit out of your zone, but wonder if you recommend anyone i should speak to in this area?
    Thank you for your help.

  4. we have a poinciana that would probably be 30+ years old (if planted when the house was built). a couple of years ago we took out some palms that were growing next to it. we had to cut back the poinciana in the process (plus the branches were getting too close to the house). this year I’ve noticed a lack of foliage – there is some but it seems sparser than previous years and recently signs of borers.

    so far they are only in a dead branch (we had tree bromeliads roped there but some strong winds blew them down which was when I noticed the holes). I’m concerned about them moving to the main part of the tree and killing it so would like to know the best way to help the tree along.

    I’ve read that there is no real chemical way to get rid of the borers (whewh), but would like to know the best things we can do to help the tree become healthy. I’m not sure of the soil type – we live near Beenleigh so what ever is there.

  5. Hi, I have 3 poinciana trees. The house has been vacant for a number of years. 1 tree has very little folliage and the bark has begun to peel off. I have had one person in to say that it has died of thirst and to cut it down as it will never recover. Another said its possibly fungi. I have photos, if I could send them. I’m not sure what to do. I live in Dampier, WA.

  6. Hi david..grt info.

    We bought 2 pinciana about 4 month ago and taken off grt.. from.small plant it would now be around 2 metre. I was windering how t9 prune and when..to form a canopy and away from house so it heads out to the street. We live mapleton next ti national park and plant thrive here..we hoping this will too.

    1. Hi Amanda. You can start training them now. Just be sure to prune branches back to ~15mm outside where they join to the previous branch and maintain balance. Also remember to undercut the branch before cutting it so you don’t strip the bark.

  7. Hi I need to prune a mature Poinciana, I was wondering what is the best season to do that, the tree is in Caloundra, Qld.
    Thanks, love your advices!

    1. Hi Jennifer. It’s not the time of year that’s important nearly so much as how it’s pruned. Poincianas react terribly to branches being ‘lopped’. They must each be collar cut. That is, each branch must be pruned back to the previous fork so the tree can seal the wound. If you phone me I’ll go into more detail.

      1. Thanks very much David for your response to my pruning question. Having enjoyed your page here so much and looked up a few other things I’ve come to a new place in my understanding of how important Poincianas are in the urban landscape and resolved to ensure that I get an arborist who knows what they are doing to prune my tree rather than just any old Tom Tree Cutter.

  8. Hi I am just going to plant a poinciana in my front yard I want it for shade how do I prune it so that it forms an umbrella shape it is 3 foot high and it has the first branches 1/2way up the trunk and then branches every 3or 4 inches apart all the way to the tip

    1. Hi Tanya. It’s great you are looking ahead and pruning for a desired outcome. We call this tree forming.

      Considering the shape of your poinciana, new growth is going to mainly be above the current branches. There will be some elongation on the lower section but most will be near the top (apical meristem). You might want to prune the lower branches to elevate the canopy, but don’t cut too many at once or you will reduce the growth of the tree resulting in a thinner trunk. Make sure you prune the lowest branches neatly by using a sharp saw or pruners cutting just outside the branch collar.

  9. Hi David,

    We live in Northgate and have a 1.5-1.8m tall Poinciana which I think was planted back in 2007 or a few years prior even. We’ve lived here for a year and it didn’t flower. Most of the street tree Poincianas in our area don’t appear to have flourished either, though there are one or two that have.

    My Poinciana appeared healthy except for its stunted growth but I must have overwatered or over fertilised it as the leaves are no longer deep green, many are falling off and what remains is a light green/yellow. I tried a light application of dolomite lime but that could have made things worse for all my limited knowledge.

    What would you do?

    1. Hi Stephen. Other Brisbane poincianas are still in full foliage so there is definitely a problem, to say nothing of the poor growth rate your tree is experiencing.

      Dolomite adds Calcium and Magnesium and can raise the pH of the soil but takes some time to work. Furthermore, many Brisbane soils already have too much Magnesium, so to raise your soil’s pH it’s better to do so with agricultural lime. Nundah in particular has red-yellow podzolic soils with red earths, so I’d be surprised if it is acidic anyway as sandstone is one of the underlying rocks.

      What would I do? First I’d check the pH of the soil. Bunnings testers are not accurate so buy some fairly tight range indicator paper off ebay or have us use our pH meter to test it for you. After sorting the soil acidity if necessary, I’d create an “exclusion zone” around the tree where no grass or large plants are permitted to grow to reduce its competitors for resources. I’d lightly fertilise the exclusion zone and cover it with a light layer of broken down mulch, followed by a generous layer of hydrophobic mulch such as woodchips.

      1. Hey David,

        Thanks kindly for the advice. What would be your callout fee to drop around, test the soil and make any further recommendations?


  10. Hi I am wanting too get married under a large poinciana tree in odour loo all botanical gardens.
    I wish so badly that they will be in red flower leaving an amazing carpet on the ground.
    Do you know of any fertiliser that may help.
    I live in far northern queensland, Cairns . I’m hooping to have a lovely red carpet November 13 ,2016 .
    Huge thanks

    1. Hi Sue. Congratulations 🙂 Phosphate is the key to encouraging poincianas to flower. If they are located in botanic gardens you shouldn’t need to worry about soil solution pH as it’s probably balanced. You can therefore just use superphosphate. It’s water-soluble so will produce fast results. Perhaps apply it a month before the big day.

  11. Hello David
    We live in Kingscliff NSW 80 min drive south of Brisbane. We purchased a ground stock 3 meter Poinciana transplanted 3 years ago when we completed our house construction. The tree is on the west side of our house the house is on the beach in a new housing estate. There is a 40 meter wide tree hedge about 7 meters high along the beachfront giving salt and some wind protection to the houses. The tree was not performing well and was replaced in September 2015 with another 3.5 meter Poinciana. The new tree seems to struggle also. It will get a flush of leaves then if there is wind the leaves get burnt off. I am wondering if I should cut a meter in height off the main trunk of the tree down to 2 meters of the ground so the tree is well below the house building height thus giving the tree some wind protection and maybe less tree for the roots to provide for. If so how would you recommend the cut be done ? Any suggestions would be well appreciated. Thank you > Emile

    1. There are limitations to good pruning, and I’m afraid you’ve reached them. Pruning your juvenile tree to that height will destroy its growth form permanently. It also won’t make it more salt tolerant. I suggest a more salt tolerant species.

  12. Hi we have a magnificent large flowering poinciana which has a couple of branches dropping with tell tale signs of borers. Can we cut out the affected branches to save the tree?

    1. Hi Naomi. The answer is ‘probably’. The longicorn borer attacks dead wood and will move into live wood if the tree is very stressed or in senescence (old age decline). If your tree is in reasonable health then removing dead wood will protect the tree from further harm. That the branches are dropping indicates it’s probably only dead wood they have invaded.

  13. My poincianas have always struggled to grow. This past summer one was green and lush and flowered nicely. Now it is dropping its leaves and is almost naked. The one next to it has been naked for months and has never bloomed??? They were planted together in 2006. Help

    1. Hi Andrea. Since you say they have always struggled, it’s probably due to either lack of water or drainage or nutrient deficiency.

      If you have sandy soil it’s likely to be a lack of water or nutrients. If you have a clay soil it’s more likely a lack of drainage. This is the short answer, call for a consultation if you would like a professional assessment.

  14. Hi David our beautiful poinciana tree comes out in bud but then dies obviously it is not well can we save it and what should we do

    1. Hi Arthur. Buds falling off can be from a lack of water or insect damage. I’d try giving it a bucket or two of water a day and also looking for insects on the buds that have freshly fallen off the tree.

  15. Cynthia Cantwell

    Hello Dave,
    We have a poinciana planted 9 months ago it is now 1.5 metres high and flourishing.It has one main central branch with 3 branches positioned around.Should we prune the centre
    branch so that a canopy will form? I have also planted the bed with perennials around the
    tree. Is it better to just have garden rocks close to the trunk to stop any unwanted infestation.
    Many thanks for your advice- we live on the Sunshine Coast.

    1. David Taylor

      Hi Kirsten. It sounds like lichen, and probably isn’t a problem. If it is fungus then it is a serious issue. I suggest googling both and contact me if it’s fungal growth.

  16. Perth – planted a poinciana in front garden from a 2m high tree to now about 5m high and about 10m in daimeter in about 7years. Unfortunately it drops its leaves all year round. Any ideas? Thanks!

  17. Hi, I planted a Poinciana tree in January 2015 and it seemed to be growing well. It lost its few small branches in the winter months and started to sprout new growth in spring. Over thelast few months being very humid and wet the new sprouts have died and the trunk looks burnt. Is the tree dead and what would cause this?

  18. Hi,
    I have planted a poinciana tree in my yard, which has beautiful new growth on it. The new growth is starting from the bottom and I’m wondering if I need to prune any of these branches which are low to the ground or do i just leave it.?

  19. Hello David ,

    6 weeks ago I planted a poinciana , i live in Fremantle WA . yesterday some of the young green foliage suddenly showed yellow leaves with a few small back spots . Most of the foliage is healthy with only a small area showing yellow .The temperature was high yesterday at 37,degrees. Blustery early morning breezes The tree had been watered in the early morning that day. Would this be a type of mould that can be treated with white oil or similar .
    Many thanks

    1. David Taylor

      Hi Cade. First look for the presence of leaf sucking insects still on the leaves. If there are any then treat with white oil on a cool day (or in the evening). If not then treat for mould by spraying with one teaspoon of tea tree oil (it must be made from Melaleuca alternifolia) per cup of water. Don’t rinse it off.

  20. Hi,
    we recently bought a house with a huge poinciana in Beachmere, I would like suggestion about a good arborist to prune her and some advice about the roots.

    Thank you


  21. Hi David
    We moved into a property last year and acquired a poinciana, probably about ten years old.
    The problem is it has hardly any flowers. Is there anything we can do to improve it?
    It sits on a sunny, windy corner of the garden where the soil is, I would say, poor. Nearby, in other properties, there are beautiful trees.
    I hope you can help!

    Thanks Jude

    1. David Taylor

      Hi Jude. It can take ten years for poincianas to flower, it’s quite normal. Soil remediation might be advisable. The first step in doing so would be to have the soil solution pH tested, though you could start with some good mulch.

  22. We have had an approx. 6 year old tree planted two years ago professionally. It is now about 3 metres tall.
    As we live in Perth with hot summers and sometimes frost in winter, we initially protected the tree by covering it with cling wrap in winter which seemed to work. (It was too tall last winter.) We were also told that the tree must be given “a bucket” of water daily in the summer. So far all is good. Are we correct in what we are doing? ( It loses all its leaves in winter) When can we expect it to flower? Any nasties we must look out for? Thanks for a very informative site on Poinciana trees.

    1. Hi Paulette. It could take another few years before it flowers. Poincianas are semi-deciduous so it’s natural for it to lose leaves, so long as it’s recovering well every summer. I wouldn’t contradict local advice you have received.

  23. Dear David,
    I live in Perth and have planted six poincianas on my property since moving here. Since the beginning of spring five have shown excellent new growth and the leaves are coming through well. One of them, however, is not doing well. It is two years old. Last year it was great but this year it started to “shoot” but when the new growth reached about 1inch in length it just stopped growing. The shoots are still green. It is in the same position as two of the others and all are treated the same. I can see no evidence of pest activity and all plants near it are doing well.
    I just don’t know why it is not growing like the others!
    Thank you.

    1. In urban environments there can be large differences in soil from one part of a yard to another. I suggest applying some broad spectrum fertiliser around the dripline of the tree and monitoring its response.

  24. Hi David,

    We recently moved into a new house and it has a beautiful Poinciana in the front yard. Initially the tree was not looking very good and we had several arborists over. One suggested cutting the tree down, the other 3 recommended gypsum and osmocote. Several months later the tree looks amazing, covered in lovely dark green leaves and beautiful red flowers. The tree has 3 main branches and we just noticed that half way up one of the main branches there is a small shoot even though above it there is a significant amount of foliage. One of the arborists said that this could be a sign of distress. Should this shoot be removed and this a sign of distress or is the tree recovering?

    Many thanks,

    1. David Taylor

      Hi Kristina. The shoot you refer to is an epicormal shoot. It’s growing from a dormant node in the bark and its emergence is a sign of stress. Its existence isn’t so much of an issue as the underlying stress that triggered it.

      Profuse flowering can be a sign of either good health or struggle. It may be that you are just seeing its regular yearly growth cycle. Poincianas are semi-deciduous and can look poor in spring yet robust in summer.

      If three arborists recommended gypsum I assume they tested the pH and found your soil to be alkaline which along with a clay soil indicated sodicity. If so I hope you took their advice as gypsum will replace sodium in the soil with calcium. It will take up to a year to effect the change, so you might just have to wait for the remedy to take effect.

  25. Hi David. We have a 40 year old house in the middle of a 600 sq mtr block and a huge poinciana in the back corner, among many other very large trees on all boundaries of our property.
    I was at the clothes line about the metre of the house and another 7 metres to the tree and noticed a fairly new root under foot.
    This root could be from either of the two trees on the boundary but given that poincianas are renowned for their invasive roots I’m guessing its that one.
    Do you think we should cut this ye down to amid damage to our property or will it go around the house?

  26. Hi David,

    I live in Longreach western QLD. Currently I have a number of nature Poiciana trees around my house. Currently we are in one of the worst droughts people can recall. One tree in particular (the oldest) is really struggling and has been doing so for a while now. Are these trees known for laying dormant until rain returns. Also it hasn’t been pruned for a considerable amount of time. Would it hurt to do so now whilst it is in this state.

  27. Hi David
    Our beautiful poinciana was stripped bare in the recent caterpillar infestation and I’m concerned about its ability to rejuvenate (it is a mature tree). There is some new foliage, but not extensive. Is there anything that I/you could do?
    Best wishes

  28. Hi David. I have just purchased a house in the Boonah area and there is a medium sized poinciana tree in the front yard which has two large branches that have died and are just there looking unsightly. However it has some new growth which looks healthy. My question is how should we prune the dead branches? Should they be cut back to the new growth? Can I email you photos of it? I would love this to be our feature tree so don’t want to damage it in any way.

    1. David Taylor

      Hi Melissa. If they have some new growth they aren’t dead. I wouldn’t touch them at all. Poincianas are semi-deciduous so it’s probably just getting new growth, typical for this time of year.

  29. Hi David
    I have two mature poinciana trees. They both have too many black seed pods, Is this normal? During winter they have also lost leaves thus both look so bare and seemingly dead. I would appreciate very much if you could advise me what to do.
    Many thanks

    1. David Taylor

      Hi Tien. Prolific seeding combined is due to stress. The defoliation shows the tree is unable to maintain energy production, or perhaps dieback due to insect invasion. Please have it assessed and diagnosed as soon as you can.

  30. Hi David, we have just bought a home in Cleveland and it has a large poinciana out the front. All of the other trees in the street still have a lot of green foliage yet ours is entirely covered in a mass of hanging seed pods and hardly and foliage. Is this a sign of a tree in trouble ? There is a stag horn growing on it also so I was wondering if that may be a problem ?
    Kind regards

    1. David Taylor

      Hi Scott. Prolific seeding is due to stress. Stag horns can allow entry of fungal infections. I suggest having the tree assessed, diagnosed and treated for the underlying condition causing the stress.

  31. Hello David, we have had a Poinciana planted in a front garden bed in Noosa Qld. It is approximately 2 mtr high & was in a 400 ltr bag. It looked a bit ordinary when it arrived but is looking very ordinary now, several branches have dropped leaves & others are rather yellow. I am concerned the area it is planted may be quite wet & wonder if this could be the problem? Any suggestions for me would be greatly appreciated please.
    Many thanks & regards,

    1. Steph, transplanting trees is fraught with issues. Because of that I really can’t say whether you have a specific problem or if your Delonix is just suffering from the move, which does stress them.

      Drainage is important and poincians don’t like wet feet. Whether or not it’s the issue, your tree won’t thrive without good drainage.

  32. Carol McCormack

    Hi David

    Our Poinciana is around 10 years old growing in rich brown soil in Lennox Head NSW. It has developed a couple of recessed oval patches, one on the main trunk and now one on an upper branch. Should I be concerned?

    1. Hi Carol. Poincianas do that. It happens when a tree grows well, outgrowing its bark. I wouldn’t be concerned.

  33. Hi David,

    We have a large Poinciana Tree over 100 years old in an adjacent property. With the sudden cold snap a percentage of the leaves are yellowing. Is this normal?


    Keith.. June 4th, 2015.

    1. Hi Keith

      Yes, cold and dry weather triggers yellowing and dropping of older leaves. I’d only be concerned if new leaves are yellowing. The older leaves will also yellow in the case of Nitrogen deficiency but it’s still likely to affect leaves more uniformly than if it’s just from the weather.

      Regards, David.

  34. Hi David,

    I planted a poinciana about a year ago in the hope of growing a lovely shade tree. Its growth rate to date has been phenomenal. It’s currently approaching about 3m tall, but the problem is that there are only two main branches. I.e. At about 1.6m from the ground, the trunk forks with each of the forked branches subsequently containing the little limbs of leaves.

    Do you have and tips or suggestions as to how I should prune the tree to encourage more of a ‘primary’ branch network/structure (as opposed to just the fork), I like how the poinciana typically forms a canopy however, at this rate due to the fork, we will only get branches and growth on opposite side of the tree/trunk.

    1. Hi Clive

      Thanks for your excellent question. I have zero tolerance for co-dominant leaders on excurrant trees, those which should have one central leader. The join lacks a branch collar, which means a loss of strength that is unacceptable. Neither can be trusted to support the weight required of them as the tree matures.

      Poincianas are quite different, being decurrent. This means they naturally branch out and the angle is likely to avoid trapping bark (included bark causes a lot of structural weakness). In other words, your tree is probably fine structurally. You will notice that its growth spurt will slow a lot as it now has to share growth hormones between the two leaders.

      As for wanting more than two leaders, you should see scaffold branches grow from the two you now have. These branches will form the real canopy in time. It’s a matter of patience for you now, but I think you’ll be happy with the long term results. Poinciana canopies tend to fill out quite spherically from the trunk along a high horizontal plane as the tree matures. I wouldn’t suggest any pruning at this stage.

  35. Hi, Could you please help me with some advice – and quickly….lol
    I live between Townsville and Charters Towers in North Qld on an old cattle farm. I have a row of mature yellow poinciana trees along the front of my house, which keeps the heat at bay in summer, but does limit my gardening prospects a bit. In desperation, I have heavily mulched (18 – 20 inches) around the base of these trees with mixed aged manure, leaf litter, grass clippings and sugar can mulch. I have planted some smaller shade lovers like clivia and broms in these gardens. Now my question, am I risking fungal diseases developing in my old trees by applying this deep and at times damp mulch and garden material around their bases? Should I remove it all back to ground level to ensure my old trees survive? Please help, I don’t want to risk losing my lovely old trees that are such good protection for us in this harsh climate.
    Thanks and kind regards,
    Jo P.

    1. David Taylor

      Hi Jo

      Yes, you are running risks having the green mulch under your trees. It is always better to let mulch break down first. Besides fungus, green mulch actually uses nitrogen rather than supplying it, so can cause a drain on the trees nutrition. It can also harbour insects such as the poinciana caterillar.

      Personally I’d probably just remove it away from the trunks of the trees and monitor them rather than move it away and then back now that it’s there, though. If you notice older leaves looking yellow or faded then apply a high nitrogen fertilizer. If you notice defoliation (the tree losing leaves) contact me immediately. Again, make sure the mulch isn’t against the trunks and you’ll avoid a lot of other potential problems.

      It’s also worth bearing in mind that a lot of Australian soils, especially ‘out back’, tend to be a bit acidic, and a lot of mulch can aggravate that. I suggest you test your soil solution with indicator paper that you can buy from a chemist. Don’t use the cheap test kits from large stores as they aren’t known for accuracy.

  36. I have a royal in my backyard that is over 10 meters high. I assume it was planted shortly after my house was built 100 years ago. It has been stripped bare by these green cabbage moth caterpillars. It took about 3 weeks and I thought it was the autumn deciduous habit but unfortunately not. Nobody has ever seen anything like this. The cacoons are all over the murraya, lilly pilly, fence and liquid amber. There are literally thousands. I have also noticed them under the house in all textiles; even socks and boots. I have tried Pyrythrum to no avail and now resorting to carbaryl. Unfortunately I cannot reach the high branches – it’s just too high. I might be too late as it seems they have eaten everything on the Poinciana and now leaving it alone to decimate the rest of my garden. I have lost sleep over it and really worried that the tree may not survive without any foliage. Any advice would be extremely helpful. The band trick might be too late in my case.

    1. Hi Matthew. I’m pleased you are looking for a solution. In past caterpillar plagues many trees have died in the following year, so your poinciana is certainly in danger.

      I really recommend against spraying Carbaryl. It’s contact only, and caterpillars are great at hiding during the day. By spraying with Bt, their food source is infected, and it’s not a chemical that can harm people and, importantly, kill the beneficial insects that are feasting on the caterpillars. Of course, I can spray all over the tree including high branches as I’m a climbing arborist. Let me know if you would like my help.

  37. Hi, there is a real problem in Barton Road and Gordon St, Hawthorne. The trees closer to the river have been striped bare and the worm/moths are working their way down the street. Lots of crows eating the worms. I’ve just found the tree in back yard has been attacked but I’m hoping to save the front one. I spoke to an older guy who said he hadn’t seen anything like this for 30yrs. Some of the trees are totally bare! Look dreadful I wonder if council would do something? I’m going to try the band method, but also going to spray any I find tonight.

    1. Hi Lisa

      Council have said publicly that this is a problem for homeowners to deal with themselves. It’s good you are going to use a band. I’d be happy to drop by with some horticultural glue over the weekend as a complimentary service for you, but what are you going to do about the caterpillars already in the tree? They need to be sprayed with Bt.

      Please don’t use chemicals. They are less effective than Bt as they can only be used to kill on contact and will harm the beneficial insects trying to clean up the caterpillars.

      Did you read my post on the poinciana caterpillar, by the way? It has a lot more information on how to treat your poinciana.

  38. Have just read your blog regarding infestation of inch worms in poincianas. We have two (front & back). We are experiencing all of the problems re them (inch worms) at the moment. Can you help us with aggressive treatment as we have a wedding party here in two and a half weeks (May 2nd) and we may not have any foliage left by then???. Will try the collar treatment in the meantime. Hope you may be able to help professionally. Mob 0417 xxx xxx address 12 xxxxxx Road, Kelvin Grove.

  39. We have a magnificent Poinciana Tree in our garden but it is covered in small green caterpillars (inch worms). They get into the house to spin there cocoons and their droppings cover our pathway. Is there a way to get rid of them? They are a real problem to us. We have sprayed them numerous times with Yates Nature’s Way Caterpillar Killer to no avail. Does anyone have an answer to this problem?
    Regards…..Mike and Jill Hogan

    1. Hi Mike, Hi Jill,

      My philosophy is to use mechanical means of pest control first, organic second and chemical third. That suits treatment for this pest well.

      The first way to sort out this pest is to wrap a sticky barrier around the trunk. It will stop the female catepillars crawling up to where they will mate, so really stops the cycle. You can use an old bicycle tube split down the middle, wrapped around the trunk and held in place with staples (it’s nice to pull them out afterwards) for a barrier. Then, coat the tube with horticultural glue which remains sticky. I like the one available from greenharvest.com.au. They also sell tree bands there, if you prefer a nice looking barrier.

      Secondly, Bacillus thuringiensis (Bt) is an organic biological control agent you can spray onto the catepillars when they are small to kill them. It won’t harm humans, animals or bees. It’s also available from Green Harvest.

      If the above two methods don’t work, and I admit they won’t beat a heavy infestation, you’ll have to resort to Maldison. You can buy it from produce stores or ask an arborist or to apply it for you.

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