How to remove grass from Murraya garden bed and care for Murraya?

[zhangsuz]

Hi everyone,

We planted our Murrayas about three years ago with weed mat and mulch, but they haven’t been growing much and are looking a bit unhealthy with quite a few yellow leaves. We fertilise them once a year.

The grass from our neighbour’s side has started to overgrow and become quite invasive around the Murrayas. We’ve been digging out the excess grass by hand, but it just keeps coming back, so it’s not really sustainable. Would installing a garden edge help stop the grass from coming through from the fence? If so, any suggested garden edge material? And is there a better or more efficient way to remove or control the grass without harming the Murrayas?

Any tips or advice would be greatly appreciated!

Thanks so much!

[EricL]

Hello @zhangsuz 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your murraya.

It looks like your Murraya hedge is struggling a bit due to a combination of soil competition, possible nutrient depletion, and root intrusion from the neighbouring lawn. Let’s go over your situation in detail and what you can do to restore them to good health.

First, yes, installing a garden edge will absolutely help reduce grass encroachment from your neighbour’s lawn. The key is to choose a barrier that extends at least 15–20 cm below the soil surface to block rhizomes (grass roots) from creeping into the Murraya bed. Steel, aluminium, or heavy-duty plastic edging works best for this kind of root barrier, as timber sleepers or shallow bricks typically don’t stop grass runners. 

For a long-term and tidy solution, use a metal edge such as Tuff Edge 2m Brushed Alloy Aluminium Garden Edge - 6 Pack or Jack 1180 x 130mm Galvanised Steel Interlock Garden Edging that sits flush with the ground surface but extends deep enough to form a proper barrier. If you prefer a more budget-friendly option, The store also carries deep poly or HDPE garden edging rolls such as the Icon Plastics 150mm x 10m Slate Grey Garden Edge that can be partially buried to achieve the same effect.

Second, regarding grass control, manual removal is only a temporary fix because couch and kikuyu roots will always regrow from fragments left behind. You can suppress regrowth by first trimming the grass close to the soil, then laying a fresh layer of thick weed mat or cardboard and topping it with 5–8 cm of mulch. Avoid piling mulch against the Murraya stems to prevent rot. Alternatively, for a more precise approach, you can spot-treat invasive grass runners with a glyphosate-based herbicide using a small brush or sponge applicator, being very careful to avoid contact with the Murraya leaves or roots.

Third, on the health of the plants themselves, the yellowing leaves and slow growth suggest they may be nutrient-deprived and slightly root-bound from soil compaction. Fertilising once a year is too infrequent for hedges, as they are heavy feeders. Start applying a slow-release balanced fertiliser (such as Scotts Osmocote Plus Organics 1.5kg All Purpose Plant Food And Soil Improver) twice a year, in early spring and mid-summer. 

Supplement with liquid seaweed or fish emulsion every 4–6 weeks during the growing season to stimulate root health and foliage colour. It also helps to gently aerate the soil around each base with a garden fork and water deeply once or twice a week rather than shallow frequent watering, to encourage deeper root growth.

Lastly, pruning lightly after fertilising will help promote bushier regrowth and better screening. Avoid cutting back too hard until the plants show healthy new growth again.

Here is a handy step-by-step guide: Planting, Growing And Pruning Murraya Hedges

Please remember to wear personal protection such as gloves, goggles and a mask when using chemicals in your garden.

If you have any other questions we can help with, please let us know.

Eric

[zhangsuz]

Hi Eric,

Much appreciated for your prompt and very detailed advice. This is very helpful and I will follow your step by step advice. 

Hopefully this will give our murrays new life.

Cheers,

[zhangsuz]

Hi Eric,

May I ask whether I need to remove the existing old weed mat first before putting on a new weed mat? Or can the new mat lay on the top of the old one? Do you have any type of mulches that you can recommend? Should I top up some new soil as well?

Thanks

Suz

[JacobZ]

Hi Suz (@zhangsuz),

There's no real need to remove the old weed mat if you don't want to. You can just lay it over the top of the existing one, keeping in mind that if you plan to do further planting, you will need to dig through two layers of weed mat to plant your plants.

For your mulch, I'd suggest a course wood chip mulch like this Richgro 70L Pine Bark Mulch.

If you felt the need, I'd top up the soil by mixing in some compost as opposed to a garden soil mix. Although this would require you to remove the weed mat so you can turn it through the soil. It is up to you, but I don't think there's any great need to add soil. Over time, the mulch will break down and top up the soil anyway.

Let me know if you have any further questions.

Jacob

[zhangsuz]

Excellent, thanks Jacob