How to revive grass tree with yellowing leaves?

[saraal1]

I'd love some advice on my grass tree. The leaves started to go yellow during the hot weather. We increased watering frequency and all the leaves but a few have gone yellow. Can you kindly advise what I should do or is it too late?

[Jason]

Welcome to the Bunnings Workshop community @saraal1. We're pleased to have you join us and trust you'll get loads of helpful advice and project inspiration from our wonderful members.

Could you please provide some more information so our members can assist? Where are you based and what kind of soil do you have? What is the history of the tree - is it newly planted or very established? What was your watering regime before the recent hot weather? Finally, if you dig down into the soil, how wet or dry is it? Grass trees are particularly susceptible to root rot.

Thanks,

Jason

[saraal1]

Thank you very much.

I am located in Sydney. The tree would have been planted approx 6-12 months ago but we only purchased the property about 4 months ago. The leaves were green when we moved in and I have to admit we weren't watering it regularly as the weather wasn't too warm and we had the occasional rain. I haven't dug into the soil but will do so if that'll be helpful. I have only a few green leaves left and was wondering what I can do revive it if it's a possibility. 

[saraal1]

Thank you very much.

I am located in Sydney. The tree would have been planted approx 6-12 months ago but we only purchased the property about 4 months ago. The leaves were green when we moved in and I have to admit we weren't watering it regularly as the weather wasn't too warm and we had the occasional rain. I haven't dug into the soil but will do so if that'll be helpful. I have only a few green leaves left and was wondering what I can do revive it if it's a possibility. 

[MitchellMc]

Hi @saraal1, 
 

One thing to keep in mind is that grass trees can be quite difficult to transplant. Their roots are very sensitive, and any disruption can cause stress or even long-term damage to the plant. Since yours was planted 6-12 months ago, it may have gone through some shock already. This could be a case of a tree that has failed the transplant.

Your grass tree might be suffering from stress due to inconsistent watering, especially with the recent hot weather. Grass trees are quite resilient but can be sensitive to changes in watering and soil moisture, particularly if they haven’t had a consistent watering routine since being planted. Before taking any further steps, it’s important to check the soil moisture. If the soil is very wet, it could be a sign of overwatering, which might lead to root rot. On the other hand, if the soil is dry, dehydration could be the cause of the yellowing leaves. Grass trees prefer well-drained soil, and while they do need water, overwatering can be harmful.

To help revive your tree, start by checking the soil around the base to see if it's too wet or dry. If the soil feels soggy or smells musty, root rot could be an issue. Next, gradually return to a more regular watering schedule, ensuring the water drains well and doesn’t sit around the roots. During hot weather, grass trees should be watered deeply but infrequently. It's also a good idea to remove any yellowing or dead leaves to reduce stress on the tree and encourage new growth. 

Let me tag one of our resident horticultural experts @Noelle to see if she has any thoughts.

Please let me know if you have any questions.

Mitchell
 

[saraal1]

Thank you very much.

[jedstur]

 

 

Hi, we’re experiencing something similar with our grasstree. It’s been professionally planted in heavy clay soil for a year now, and did very well in the first 11 months (even growing a huge flower spike!)

In mid-December I cut the flower spike off after it had stopped flowering and weather started heating up. I also bumped the drip irrigation up to 15min/day 3x a week (which I since learned is likely way too much!)

Then the leaves started yellowing and even young growth in the centre of the crown started looking like it was dying or drying out. There’s been no new growth since cutting the flower spike off either, which has me concerned.

It hasn’t gotten any better since scaling back the watering. If anything the yellowing is slowly getting worse.

Any ideas?

[MitchellMc]

Welcome to the Bunnings Workshop community @jedstur. It's sensational to have you join us, and many thanks for your question about grasstree care.

Thanks for sharing the details and photos of your grass tree. It sounds like you've been keeping a close eye on it, which is great. What is your current watering regime, and when did you switch to it from the previous one?

If the grasstree was overwatered for a time, the roots may have been stressed, and it might take a while for the plant to recover fully. Grass trees are very sensitive to their conditions, especially when it comes to watering. They prefer deep, infrequent watering rather than regular, shallow watering. Letting the soil dry out between waterings is essential, especially in heavy clay soil, which can retain moisture for a long time.

Please let me know if you have any questions.

Mitchell
 

[jedstur]

Thanks for the reply @MitchellMc .

Sometime in December when the weather started heating up, I upped the drip irrigation to my whole garden to be 3x15min per week. That was enough to sadly kill my baby grasstree (also planted professionally into our heavy clay garden bed), so it’s possible it stressed my large one too. Currently I’ve switched the irrigation off and water everything else there manually every week, avoiding the grasstree (that now gets a deeper watering less frequently).

I read somewhere that the microbiome in the grasstrees soil like getting a dose of water mixed with brown sugar water, approx. monthly - is this true?

[EricL]

Hello @jedstur 

Using brown sugar helps a particular fungus called mycorrhiza. The mycorrhiza are beneficial fungi that help the tree's roots absorb nutrients and process water. However, using this method requires patience as it needs to be done once a month for the next two years. I propose instead using Seasol 600ml Complete Garden Health Treatment to help invigorate your grass tree.

If you need further assistance, please let us know.

Eric

[jedstur]

Thanks @EricL , I actually used to Seasol the grass trees for years when they were in their original pot before we planted them. It seemed to do well over time, so I’ll give it a go.