Angus StewartHow to prune a flowering gum

The red flowering gum (Corymbia ficifolia) is one of the world’s most spectacular trees when in full bloom and in recent times the development of more compact cultivars that are propagated vegetatively (usually by grafting) has made this an even more popular choice as a feature tree for the garden.

How to prune a flowering gum

Vivid pink flowering gum

Vivid pink flowering gum

Pruning a young plant
When you first plant a flowering gum it is a vital time to shape it according to your design tastes. If, for instance you would like a compact ball-shaped specimen with maximum flowering then you should choose one of the more compact grafted cultivars that are available, especially from specialist native plant nurseries. Tip prune your new plant every couple of months through spring, summer and autumn for the first year after planting and you will develop a dense framework of shoots that will usually produce a more prolific flowering display the following summer.

An exception to this approach is if you want to develop a taller tree with a clean trunk to go at the back of a garden bed. In this case you will want to prune off any lower shoots and leave the strongest shoot to grow at the top of the plant. In my experience, however, most people want to keep their trees compact and as low as possible so it really comes down to what you wish to achieve with regard to the shape of your tree.

Pink flowering putting on a good show in late January

Pink flowering putting on a good show in late January

Pruning after flowering
The most critical pruning operation with your flowering gum once it is established is to prune it as soon as possible after it finishes flowering. A series of physiological changes happen during and after flowering if the tree is left to its own devices. The first is that the plant starts to put a lot of energy into the formation of the gumnuts, and if this process goes too far it seems to inhibit the production of flower buds for the following year. The second thing is that the tree kicks into vegetative growth that comes from the buds directly behind the spent flowers, and this means that the tree will just get taller and taller if it left to its own devices.

Pruning a flowering gum - As soon as the flowers fall is the time to prune

Pruning a flowering gum – As soon as the flowers fall is the time to prune

Pruning a flowering gum - Flowering gum before pruning in early February. The tree is starting to put energy into forming gumnuts

Pruning a flowering gum – Flowering gum before pruning in early February. The tree is starting to put energy into forming gumnuts

Pruning a flowering gum - one month later, the trees flowers are spent and gumnuts are forming - time to prune!

Pruning a flowering gum – one month later, the trees flowers are spent and gumnuts are forming – time to prune!

Pruning a flowering gum – using heavy duty loppers to reduce the tree’s height and cut into older wood

The bottom line is that it is extremely beneficial to prune as soon as possible after flowering to give you the best possible chance of a good flower display the following year. My preference is to prune the tree in such a way as to ensure there are lots of flowers at eye level as well as at the top of the tree (depending on the mature height of the cultivar in question). This can mean reducing the tree by 30% or more in height each year depending on your growing conditions. A set of heavy duty loppers can be a very handy tool as flowering gums are capable of considerable growth in a single year.

Pruning a flowering gum - make sure to prune just above a leaf bud, or node

Pruning a flowering gum – make sure to prune just above a leaf bud, or node

When pruning behind the flowers, ensure that you take each back to just above a node, preferably one where a small shoot has already emerged. Generally, these small shoots will kick into growth straight away and provide the flowering branches for the next blooming the following summer. This is also a great time to feed the plant to help ensure good growth straight away that will set up the framework for the next flowering. Even though flowering gums are not particularly sensitive to phosphorus I still use a low P fertiliser in my garden to ensure that any phosphorus sensitive plants such as banksias and grevilleas are not compromised.

Pruning a flowering gum - Flowering gum after pruning in late summer

Pruning a flowering gum – Flowering gum after pruning in late summer

Pruning a flowering gum - after pruning, the tree is ready to make new flowering stems

Pruning a flowering gum – after pruning, the tree is ready to make new flowering stems and there will be a good display at eye height too

Pruning off rootstock suckers

Pruning off rootstock suckers

Maintenance of the rootstock on grafted trees
The vast majority of flowering gum cultivars are grafted plants so it is well worth checking the graft union at the bottom of the plant. If there are any new shoots emerging from the base of the plant these should be removed while you are pruning the top of the plant. If they are left to grow they will tend to swamp the growth of the scion that is grafted on top that you are wanting to encourage.

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Angus Stewart

About Angus Stewart

Gardening Australia TV presenter, author of 'Creating an Australian Garden', 'Australian Plants for Year-round Colour' and 'Let's Propagate', garden travel guide, native plant specialist and breeder. Central Coast, NSW. Find out lots more about native plants at Gardening with Angus.

19 thoughts on “How to prune a flowering gum

  1. Carol Griesser on said:

    Thanks, Angus. Very useful information!

  2. Lois Davey on said:

    Ive had two dwarf flowering gum for 5 years and hardly any flowers after first year so last year I took of all gum nuts and this year they flowered, not much, so I’ve
    just gone and tip pruned them as you said so thank you for that information.

    • Hi Lois,
      Give them a feed and a water right now as well and I would virtually guarantee a result for next summer.
      Cheers
      Angus

  3. Ken Shearing on said:

    Angus, we have a grafted flowering gum with sparse leafing until the branch tips. It flowers well in this area however the tree looks short of foliage – leaves only at the extremity of the branch. Further, I find there is a lot of dead twigs which I remove but the tree looks bare. Is this a common trait of this type of grafted miniature and can I prevent it? I have just finished pruning after a flowering. Best wishes..Ken

    • Hi Ken
      Apologies for not getting back to you at the time you wrote in. It is hard to say whay us happening workout seeing the tree in situ but I would suggest that heavier pruning after flowering would help to create a smart canopy for your tree.
      Cheers
      Angus

  4. Anne Wright on said:

    Hi Angus, my dilemma is my orange flowering gum. It is in a pot (and has been for at least 5 years) but all its leaves are now brown, looks totally dead but the stems are still green when scrapped. Is it too far gone or will a good all over prune help it to rejuvenate. Im guessing not much further harm can possibly be done by trying, what do you think?

    • Hi Anne
      Apologies that I did not get around to answering you when you wrote in. I hope you food go for a ‘renovation’ prune as that would definitely have been my advice.
      Cheers
      Angus

  5. Rhonda McKenzie on said:

    My red flowering gum is in flower at the moment. it seems to flower every 2nd year in my coastal garden.. about 4 hours north of brisbane. I had trouble with suckers one year but so far no more have grown. My plant seems to be growing at an angle, possible because of the wind we have here. This is quite a harsh environment so Im just pleased it has survived albeit with a rather strange shape to give me a heap of xmas flowers. thanks for your advice.

    • Hi Rhonda
      It is never too late to shape your tree with judicious pruning! Good luck with it.
      Cheers
      Angus

  6. Bob Patrech on said:

    Hi Angus I purchased 5 flowering gums but they were definitley not grafted and have been in the ground for around three years how long does it take a flowering gum to flower and how can I tell if these are in fact flowering gums they look awfully like a normal gumtree to me Regards Bob

    • Hi Bob – seed-grown Corymbia ficifolia will usually take between 5 to 10 years to produce its first flowers. The flower colour could be red but, as seed-grown plants have great genetic diversity, they could also turn out to be pink, white or orange.

    • Hi Bob
      Apologies for not replying earlier. Catherine’s advice is all correct. As for telling what species they are they should have rough bark that is what is described as tesellated ( chunky in appearance) a google images search will show what it should look like. The leaves will be broad and glossy and the colour of the leaf veins will be an indication of flower colour ie the darker the colour the darker the flower is likely to be.
      Cheers
      Angus

  7. Judith on said:

    Hi Angus I have a red flowering gum that is up against the corner of the house. It is about 4 meters high now. Would the roots be doing any damage to the house? If I cut it back to a manageable height and kept it pruned there would the roots continue to grow or would they stay at what they are now.

  8. Suzanne Tinker on said:

    Hi we have a flowering gum about 4 to 5 years old but its very spindly ,when it has flowers they hang down,the trunk isnt very thick either, do i prune it.

    • Hi Suzanne
      Yes I would prune the branches back by half after flowering.
      Cheers
      Angus

  9. Jo dinn on said:

    I think I have done something terrible . We planted a red flowering gum . It is one year old and we cut off the lower branches ( thinking lower branched might get thin the way of the roof ) I thought I read to do this somewhere in its second summer . Now I am so worried that I have created a tree that will be top heavy – or maybe more branched will now come up so there will be mid branches missing ? As I have now read wait till it is 6 feet talk . Old let me know if this will be a large unbalanced tree or it should be ok ? Thanks for this . JD

    • Angus Stewart on said:

      Hi Jo
      I do not think you have created a disaster. As I mentored in the post it is certainly am option to prune lower branches to develop a taller tree. This could work particularly well for a seedling flowering gum that is likely to be well anchored. Grafted trees sometimes end up with unstable great unions at the base of the tree. So rest easy I think your tree will be fine.
      Cheers
      Angus

      • Jo on said:

        Thank you so much for this . I feel a lot better now – it was a very important memorial tree !

  10. Helen Muscat on said:

    Hi I have a flowering gum that has grown outwards rather than upwards, how far back can I prune the outward branches?
    The branches stretch out far, some 1.5 – 2metres. Can I cut them back down to 1/2 metre?.
    The middle of the tree is very bare and all the growth is on the ends of the lanky branches, I”m scared if I cut them back nothing will grow in the centre.
    What do you suggest.
    Helen

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