How to stop newly planted Murraya Hedges dying?

[pkhedkar07]

Hello,

Appreciate your help. Last year, I planted 70+ murraya hedges along the front boundary perimeter facing east, northeast and north directions adding fertilizer at that time. All of them have a weed mat and cowra white 40mm pebbles underneath. 

The ones on the east and north east side are growing ok however, the ones on the north side are either dying or yellowing out with hardly any growth. I have been providing slow release granule fertilizer and seasol tonic to all periodically but don't see any improvement.

I am unable to figure out what is the issue which is affecting some of them but not all. If weedmat and pebbles is the problem, not sure why it affects only the ones on the north side.

 

 

 

[JacobZ]

Hi @pkhedkar07,

A warm welcome to the Bunnings Workshop community and thank you for your question.

Did the plants on the north side grow well to a point and then suddenly start to struggle? Did you add any soil to the garden beds when you were planting the murrayas?

If the plants were growing well and then they suddenly started to struggle, I suspect the issue is likely due to soil conditions and the retention of water in the soil under the failing plants.

The soil underneath could be heavy in clay, which can cause it to retain too much moisture, which can lead to waterlogged roots. This can stunt growth and cause yellowing or dying plants.

We'll need to do some investigating to confirm or disprove my suspicions. Can I ask you to pull back the stones around the base of the struggling trees and upload an image of the soil beneath? Is it similar to the soil underneath the plants that are thriving? How moist is it?

If it is as I suspect an issue with the soil, then the best course of action would be dependant on what you find.

It could be to aerate the soil with a hand fork and add organic matter in the form of compost or manure to encourage microbial growth and burrowing insects in the soil. If you find there is a heavy clay layer, applying gypsum to the soil and mixing it in will help to break up the clay.

It would also be worthwhile to test the pH balance of the soil with a Manutec Garden Care Products Soil PH Test Kit. If the soil is outside of the recommended range, between 6.0 and 7.5, then we should take steps to bring the soil back within this range. Have a look at How To Test And Adjust Your Soil pH for some guidance.

Allow me to tag some of our experienced gardeners such as @Noelle, @mich1972 and @robchin for their thoughts.

Let me know what you find when you inspect the soil around these plants. I am happy to assist further if required.

Jacob

[pkhedkar07]

Hi Jacob,

Thank you for your reply. Attached is the photo of soil underneath the Murrayas having issues... On touch, I didn't find it any different to the soil underneath the good ones.FYI I am using soaker hose lined along the murraya roots and run it for 10 mins 3-4 times a week.

To answer your other questions, 

My landscaper did add the new soil and slow release granule fertilizer to all the plants back in May 2024 and I sprinkled again in Dec 2024. I have used seasol gold liquid twice so far.

When these were planted, all were looking ok but I started noticing few dying out of yellowing of leaves in Nov 2024.

 

 

[EricL]

Hello @pkhedkar07 

Thanks for sharing those extra photos of your Murraya hedges.

It sounds like you’ve put a lot of effort into caring for your murraya hedge, so it’s frustrating to see some plants struggling while others are fine. The fact that the issue is mainly on the north-facing side suggests it could be environmental. One possibility is heat stress. The north side likely gets more direct sun, and the Cowra white pebbles can reflect heat back onto the plants, making the soil hotter and drying out the roots faster. Adding a thin layer of organic mulch, like sugarcane mulch, could help keep the soil cooler and retain moisture. Also, check if the leaves look scorched or bleached, which would indicate sunburn.

As Jacob mentioned soil drainage or compaction could also be a factor. Even if the soil feels the same in different areas, slight differences can affect how well water is absorbed. If water is running off or not soaking in deeply enough, the roots might not be getting what they need. You could try aerating the soil lightly with a garden fork and using a soil-wetting agent to help moisture penetrate properly.

My only other thoughts on what could be causing the imbalance is watering. A 10-minute soak, 3-4 times a week, may not be reaching deep enough, especially with the heat. Instead of frequent short watering, try running the soaker hose for 20-30 minutes twice a week to encourage deeper root growth. This will help prevent the plants from relying too much on surface moisture. This is on the condition that your soil is not heavy in clay content.

To get to the bottom of it, start by checking the roots of one struggling plant. Adjusting watering, adding mulch, and supplementing with a soil-wetting agent might help turn things around. Keep an eye out for any other signs, like pests or leaf damage, and let me know if you notice anything new.

If you need further assistance, please let us know.

Eric