How to treat grass tree with brown leaves?

[YoGabba]

Hello, 

For the last few months or more our Grass Tree has appeared to slowly be dying and I fear it may already be dead. We have moved in to a fairly new property, so have little familiarity with this tree.

First, the tree flowered (mid 2024) as pictured. The leaves/grass was green at the time. 

Second, at the start of January 2025, the leaves began to brown, more and more - though there were some green leaves in the middle. At this time I noticed there were black dots on the leaves, which I concluded may be scale (see picture). I sprayed the leaves with "Eco-Oil" once a week for three weeks. I also tried to manually wipe the scale off, but was difficult to get them all. I also watered the tree with "Seasol" two or three times, about 5L each time. I th

en trimmed some of the dead leaves at the end of January. 

Third, the leaves still, perhaps more slowly, began to brown. Until recently (end of February) while we were away the leaves all fell off the tree. The flower/spike began to tip over and I pulled it off a few days ago. 

I read it is natural for Grass Trees to appear to 'die' after flowering, but I think ours is beyond that. I'm not sure if ALL the leaves are supposed to fall off. Our neighbour has the same tree, which also flowered at a similar time, but their leaves are very green with no brown, and their spike has not fallen off.

I read conflicting things about whether I should water it or not. I also heard perhaps burning it with fire could be helpful. It may be root rot but I don't know how I can tell without digging down to the roots. 

Any help would be helpful. Thanks in advance. My main questions are: 

1. Is this all just a natural process that occurs after it flowers? (Judging by my neighbour's tree it seems unlikely)

2. What might be the cause of dying? I don't think the 'scale' could kill the tree this much, could it? 

3. What can I do now to revive the tree? 

Thank you once again. 

End of February 2025End of February 2025, Leaves Fell OffStart of January 2025, ScaleStart of January 2025, BrowningEnd of January 2025, after TrimMid 2024, Flower/Spike

[JacobZ]

Hi @YoGabba,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Grass Trees can decline due to stress, poor drainage, pests, or disease. While some browning after flowering is normal, complete leaf loss is not—especially since your neighbour’s tree remains healthy.

While scale can weaken the tree, it’s unlikely to cause total dieback alone. Root rot is a likely culprit, especially if the base is soft or smells bad. Overwatering, poor drainage, or recent disturbance could also contribute. 

At this point, unfortunately, I think the only reasonable response is to contact an arborist who specialises in the care of native trees. They will be able to advise you on whether your grass tree can be saved and offer you guidance on steps moving forward.

Allow me to tag @Noelle and @mich1972 to see if they have any experiences or advice to offer.

Jacob

[mich1972]

Good afternoon @YoGabba I agree with @JacobZ with the information he has provided. Could I please just add to this. Here in Perth, Middle Swan there is a Grass Tree Specialist called Grass Tree Australia. I wondered if you could email them regarding yours. To me it looks like it’s dead but I am not a specialist with them. I’m just wondering the spot it’s growing in with all the lawn surrounding it, lots of water and also fertiliser to feed the lawn could have leached and destroyed the GrassTree ? Just my thoughts. I hope @Noelle will be able to help out too. 

[Noelle]

Hi @mich1972  and @YoGabba 

Yes, I agree with you@mich1972 regarding the location in the lawn and the potential for over-watering and too much fertiliser. Grass trees in home gardens seem to do best in gravelly soil that drains really well and isn't overly nutrient-rich - they are desert plants after all.

Contacting a grass tree specialist is a great idea and, even if you're not in Perth or even WA, the advice to be gained could make the difference  between survival, or not.

[YoGabba]

Hello @Noelle @JacobZ @mich1972,

I deeply appreciate and am thankful for your quick responses and advice on our situation. It’s sad to hear that the tree may be dead, but it wasn’t unexpected.

Thank you for directing me to Grass Tree Australia. I sent them a message for now. 

Did you have any other suggestions for what I can do in the mean time?

I have ordered “Swift Grow” because I read it can help the roots recover if there’s been root rot.

I also read burning the tree can help. I was thinking of hiring a blow torch and giving the tree a bit of a burning. 

Do you perhaps have any thoughts or advice on this or anything else?

Once again, thank you so much. 

[EricL]

Hello @YoGabba 

In the interest of health and safety, I propose holding off on the blow torch and leaving that particular step to the Arborist. They will have the knowledge and experience in regards to how much and how far to burn the tree. 

If you need further assistance, please let us know.

Eric

[Noelle]

@YoGabba 

I'd hold off doing anything at all until after you have received some professional advice from someone who understands grass trees. They have quite sensitive roots and also have a 'symbiotic' relationship with soil-borne micro organisms, where the grass tree helps the microbes and the microbes in turn assist the grass tree. In my opinion, it would not be wise to give any soil treatments until you've had expert advice.

[mich1972]

I’m not sure what else you could do in the meantime. Keep us updated if you get a response from Grass Trees Australia